The Ibera natural Reserve is located in the province of Correintes, in the northeast of the Argentine Republic, the known ecosystem as Esteros del Iberá must to their name to the Ibera lagoon located in the zone Eastern center of this immense system of humedals. The Iberá word is formed by two words of the guaraní language: ¨Î¨, water, that put in front to ¨berá¨, brilliant, in its Castilian translation to express to the site like ¨el the water that shines or brilla¨, name that supposedly gave to their original guaraníes settlers when observing the chispeante brightness him of their surface. This peculiarity is visible in its water mirrors during the aurora or anocher, when the own calm of a closed system, without fluvial currents, bankruptcy with the breeze produced by the change of temperature between the surrounding terrestrial surface and the water of the matting or lagoons, causing itself a superficial movement that reflects with very particular effects the solar light to crepuscular. Certain objection exists nevertheless on this origin of the denomination, because between the settlers the belief that still lasts the name must to heroic princess Iberá, the daughter of the guaraní cacique who submerged in the matting to protect the dignity of his culture 1. In fact this name has been evolving with happening of the time, since registries exist that they originally identify to the site like Matting of Expensive Face, because in this place the emigrated natives lived on the Mission of Santa Ana by committed crimes, knew by “Caracará”, name also given to a bird of rotten prey: the “owl” (Figueredo, 1929)

Hugged by Paraná River, Corrientes City keeps a unique architectural style which treasures relics having a great historical, religious and cultural value. In this tour , we highlight the most important sites of a city that invites one to discover it. We started the tour at the Church and Convent of Saint Francis located on Mendoza Street between De la Quintana and Plácido Martínez Streets. This building is from 1638 according to Capitular Records of San Juan de Vera de las Siete Corrientes City, being Saint Francis Solano its Patron. As you stand in front of the building, you can observe its eclectic style in the columns of the Portico which are inspired in Bernini´s work on Saint Peter´s Basilica in Rome. At the back of the church, on Italia Avenue and Quintana Street, the old convent is located, having walls, ceilings and windows of leather kept since XVI and XVII centuries.

We go on along Mendoza Street to the North until Vera Avenue and Aragón Street. We pass by the front of the building belonging to Prefectura Naval Argentina ( Argentinian Naval Prefecture), we turn right into the Avenue and ride for three blocks until Mitre Park getting through the old Bridge of "la Batería". In this place, San Pedro Battery positioned . It was commanded by General Mitre and acted in decisive moments in the War of the "Triple Alianza". Inside, there is a monument to the "Cautivas", work by Luis Perlotti which was inaugurated in 1941. This sculpture group represents the five women from Corrientes who were captive and hold hostage during that war, being only four of them released alive in the end.

As you go around the park, you can get until Punta Mitre, one of the seven points of land and stone that come out on Paraná River and which gave its name to the city- San Juan de Vera de las Siete Corrientes. From there, you can observe the full installations of the Yachting Clug with its yellow beaches and mooring with middle-sized boats. We rode back along Vera Avenue to San Martín Coastal Avenue and passed by General San Martín National School. Further ahead, the statue of the taragüi, work by Antonio Puyau that was given the First Prize in the National Art Room. taragüi was the name given by natives to the town founded by Don Juan Torres de Vera y Aragón on April 3rd, 1588 in Arazatí Point.

As we go along this Avenue, we stop to observe the colorful vegetation surrounding the coast, made up of pink lapachoes, lilac jacarandaes and red chivatoes.We find another outland over the River- it is Tacurú Point. From there, we can see "Hotel de Turismo", the casino of the city and Cambá Cuá Park ( meaning " black people cave" since this area of the city was exclusively inhabited by black people from colonial times. We turned left onto Chaco Street and rode for eight blocks until 3 de Abril Avenue while we observed the Spanish and autochthonous colonial styles of the houses in the area. On this Avenue, there is a monument that outstands, it was done to pay homage to Carlos María Alvear by sculptress Lola Mora from Tucumán. We turned onto Buenos Aires Street and went ahead until De La Cruz Square where we stopped to visit the church that contains "The Cross of the Miracles" which was declared National Historical Monument in 1942. The church was made by Engineer Juan Coll from Tucumán who did further studies in Italy and brought the new architectural style called "Italianizing".

In old times, the church had a great cupolaand two towers that were later demolished since, due to a mistake in the construction, turned out of proportion because they were too big and heavy. Since 1915, they are shorter. Inside, the main and lateral naves outstand having Medieval reminiscences and the lateral chapels having Gothic Altars. Opposite the church, De La Cruz Square is located, in the center of which the Monument in honor to Dr. José R. Vidal and to the physicians who fell on duty during yellow fever . The monument is made of bronze and the base is made of red sand stone taken from Mercedes quarry ( Corrientes). We went on the tour around the center of the city, took Buenos Aires Street to the North until Downtown Corrientes.

On 25 de Mayo Street, there is a Square called after it which is surrounded by old buildings from the period between 1880 and 1910, most of them are currently used by Public Divisions such as the Government House, the Rectorate of the UNNE, the Church of La Merced, Sarmiento School and the Police Station. Inside the Church of La Merced, there are four cedar confessional boxes which were carved by natives belonging to Jesuitical settlements and are considered real historical treasures- they are believed to have been taken from San Ignacio Miní. The Lady wears the habit of the Order of Our Lady of Mercy with the band of the Argentinian flag since Belgrano declared her General of Argentinian Army. We went along 25 de Mayo Street until San Juan Street and observed the front of Juan de Vera Theatre, being one of the most important ones due to its acoustics. Among the shows that take place here, we can mention own productions and guests casts of all genres- music, ballet, theatre, children´s shows, cinema and video cycles, didactic concerts, courses and lectures.

We go on along San Juan Street, crossing through the area of banks, Don Bosco School, María Auxiliadora Church and the Central Market. We turn onto Yrigoyen Street, ride four blocks until the Cathedral where we observe its Italian Renaissance style in its portals placed on Corinthian columns that are also found inside the building. Appart from that, there are two towers that end in little cupolas coveredby French Blue Majolicas. Opposite the Cathedral, there is a Square where the Monument to Juan Bautista Cabral- the Argentinian hero that saved Gral. San Martín´s life in San Lorenzo Battle. Junín pedestrian street starts at the square and is six blocks longuntil Salta Street where we finish the city tour and where we can get a gift to remember our stay at this city. data: welcomeargentina.com

Corrientes
Province
Flag Coat of arms
Divisions	25 departments
Capital	Corrientes
Area	88,199 km² (34,054 sq mi)
Population	930,991 (2001)
Density	10.6 /km² (27 /sq mi)
Governor	Arturo Colombi
- Senators	Isabel Viudes, Dora Sánchez, Roberto Ríos
ISO 3166-2 code	AR-W
Demonym	correntino

Corrientes, like much of the Argentine north, has long had relatively underdeveloped economy. Its 2006 output was estimated at US$4.2 billion, or, US$4,540 per capita (about half the national average).

Agriculture is still one of the main activities in the province, adding 15% to its output. It's centred in citrus, tobacco, rice, tea, cotton and yerba mate, for which it's well known internationally. The timber industry uses 1,400 km² of pine and eucalyptus forests.

Bovine cattle has problems standing the heat and the low quality of the grass specially in the north of the province. For that reason, the Brangus breed is the most common in the area. In the south, different breeds can be found. 70,000 km² of the province's land are used for more than 4 million heads of cattle.

Among Corrientes' productive (non-services) activities, tobacco and its processing earns 45% of the province's gross income, food and derivates, 30%, and textiles, 16%.

On the Paraná River, near the city of Ituzaingó, the Yaciretá dam provides energy not only to the province, but to both Argentina and Paraguay.

Tourism has been growing in Corrientes Province due to the relevance that Esteros del Ibera has for ecotourism and birdwatching travelers. Golden dorado fishing has long attracted both local and outside tourism to Corrientes.

data: wikipedia

The province is divided into 25 departments (departamentos):

Department (Capital)

1. Bella Vista Department (Bella Vista)
2. Berón de Astrada Department (Berón de Astrada)
3. Capital Department (Corrientes)
4. Concepción Department (Concepción)
5. Curuzú Cuatía Department (Curuzú Cuatiá)
6. Empedrado Department (Empedrado)
7. Esquina Department (Esquina)
8. General Alvear Department (Alvear)
9. General Paz Department (Nuestra Señora del Rosario de Caá Catí)
10. Goya Department (Goya)
11. Itatí Department (Itatí)
12. Ituzaingó Department (Ituzaingó)
13. Lavalle Department (Lavalle)
14. Mburucuyá Department (Mburucuyá)
15. Mercedes Department (Mercedes)
16. Monte Caseros Department (Monte Caseros)
17. Paso de los Libres Department (Paso de los Libres)
18. Saladas Department (Saladas)
19. San Cosme Department (San Cosme)
20. San Luis del Palmar Department (San Luis del Palmar)
21. San Martín Department (La Cruz)
22. San Miguel Department (San Miguel)
23. San Roque Department (San Roque)
24. Santo Tomé Department (Santo Tomé)
25. Sauce Department (Sauce)

Source Link: wikipedia

The entire Argentine energy system supports a smooth cold wave higher than the 2007.

Among the major projects that are making profits out raising the level Yacyreta which allowed an increase in generation of 11,900 GWh / year to 15,120 GWh / year or an additional 3,220 GWh / year, increasing the level of the reservoir 2 50 meters (from 76 m elevation to elevation 78.50 m) in late 2008.

The Ministry of Federal Planning, Public Investment and Services noted that as part of an energy policy based on expansion of infrastructure available to support growth, increased in the period 2003-2009 more than 20 percent of electricity generation capacity.

The Argentine director of the Binational Yacyreta Entity (EBY), Oscar Thomas, who attended the XXXVII meeting of presidents of Mercosur, said yesterday: "An important milestone this year is we want the height to 80 years with Yacyreta. Today we are at 78.50. That would be a very important fact, because it also involves moving strongly toward Encarnación works. That is a significant energy level. "

CAMMESA (Company Manager Wholesale Electricity Market) reported that on 23/07/2009 "was passed a record high power SADI (Argentine Interconnection System) working day for 19,566 MW, due to the very low temperatures triggered by polar wave plaguing almost all the national territory.

Sources: Buenos Aires Economic Journal, CAMMESA and Ministry of Federal Planning, Public Investment and Services.

Yacyreta The work is an example for analyzing social, political and economic history of argentina. Its construction started thinking in 1958, after forty years of Yacyreta, a responsible end. By Oscar Thomas.estudios of the most suitable for implementation. To take into account the waterfalls of Iguazu.

Of taking different decisions, almost opposite in successive Argentine governments to address the issue, we conducted countless and fruitless meetings with high-level pairs of Paraguay and the representatives of Brazil to agree to the heights of leveling of the respective dams , Itaipu and Yacyreta.

The consultants who made the preliminary studies presented several alternatives, which subsequently had to be modified.

Only one third during the presidency of Juan Domingo Perón signed the final agreement with Paraguay for the hydroelectric.

The situation in the country meant going back to talk about it only during the military government. Between 1976 and 1983 set the final project was tendered and the main contracts. There were long delays because, among other things, the Falklands War, which caused financial problems.

In 1983 he began the major work and was completed in 1998, while allowing free improvisation to the planning and execution of additional works.

The term "works" does not say anything to the unwary reader, but its meaning becomes more explicit when it is mentioned that these works involve the relocation of a considerable number of families and the protection of five cities located on the edge of the Paraná River, distant Some of them, in more than 80 kilometers from the site of the dam.

Changes in levels also imply the need to build bridges and roads, ports, public buildings such as hospitals and schools, as well as rebuilding the infrastructure affected by rising water level. In addition to responding to the latest technical knowledge, research and technology to prevent damage to the ecosystem, which contracted specialized institutions in each of these topics.

At first, it was felt the physical impact of its reservoir, but is not balanced and the tremendous social impact on cities. And, worse still, during the heyday of construction during the Menem administration, the decision was made to underfunded the project with the goal of "privatizing" and was stigmatized with the nickname of the "monument to corruption", in sealing then the stay of an integration project and causing major economic and social liabilities that must now repay.

In this context, President Kirchner, on assuming his office, took the political decision to conclude the project, in agreement with President Duarte Frutos of Paraguay.

While, as explained in a note to the nation of 5 of the current, have been completed eight years ago the civil works of the dam, installation of the turbines and their operation, the remaining works that make up today Termination of the Plan Yacyreta, which-by the decision of the current Argentine government with adequate funding for their completion.

These works are absolutely essential for the relocation of 17,000 families, identified through surveys on both sides of the enterprise, which involves a significant property of Argentina and Paraguay.

Even being projected outside of time and thus works to protect coastal cities-new tracks from sewage systems and drinking water, the resolution of the replacement of affected roads and bridges that connect the towns and cities in each room each other in an area riddled with waterways (rivers and streams) - now facing Yacyreta social responsibility and commitment to the goal of reaching the final conclusion of the project in an orderly and planned in detail by the end of 2008.

Termination Yacyreta will be complete only when it complies with the social debt that none of the previous administrations contemplated as obligations of the state with its people.

The filling of the dam height to 83 can not be done automatically, as they open a tap and fill a container, because this need to develop commitment to the people, which demands full respect for their rights, as befits a democratic context.

Nicanor Duarte Frutos the presidents Néstor Kirchner and are committed to the completion of Yacyreta in a context of administrative transparency and efficiency essential for the full generation of energy.

You must close a chapter in our history, which prevailed antinomies and lack of credibility in public institutions.

Yacyreta be completed with the participation of the people, municipalities, provincial governments and departments. This is the belief that, with well-directed work every day, you can.

The author is an architect, executive director Yacyreta.

Published in the Diario La Nacion (19-10-2006)

Before the arrival of the Spanish conquest, the Guaraní lived in a big area that also covered most of the current province of Corrientes. The city of Corrientes was founded on April 3, 1588 by Juan Torres de Vera y Aragón as a mid-stop between Asunción and Buenos Aires; the city flourished thanks to the traffic from the route. Jesuits erected missions in the north of the province, where they dedicated themselves to the expansion of the faith. In the wars of independence from Spain, Corrientes joined Artigas' Liga de los Pueblos Libres (1814–1820). The attack of Paraguayan forces on the province in 1865 marked the start of the War of the Triple Alliance.

In 1819 the National University of the Littoral was founded, which in 1956 became the National University of the Northeast.

Corrientes 3 centavos stamp, 1871.

Corrientes is legendary in the world of philately for the postage stamps it issued from 1856 to 1880. These are among the very early or "classic" postage stamps of the world (the first, from Great Britain, were issued in 1840; those by the United States in 1847). The Corrientes stamps were close copies of the first issue of stamps from France, which depicted the profile head of Ceres, the Roman goddess of agriculture, and were individually crudely engraved by hand, so that each dieis noticeably different, and were printed in small sheets. The first issues, from 1856 to 1860, bore the denomination in the lower panel; in 1860, the value panel was erased; the different denominations thereafter being indicated by the color of the paper used. As locally produced "primitives", the early Corrientes stamps have long been prized by collectors. After 1880, stamps of Argentina were used.

View of Itatí, on the Paraná River, 1892.

The Yacyretá Dam.

During much of the 19th and 20th centuries, politics in Corrientes were dominated by the Romero Feris family, large local landowners who control most of the province's tobacco output. During most of this time, the Romero Ferises created one of Argentina's most bloated government payrolls (over 10% of total employment) and suppressed dissent and efforts at even modest land reform. Following contentious election results in 1991, however, public protest forced President Carlos Menem to remove Gov. Raul "Tato" Romero Feris from office and, though he was elected mayor of the province's capital in 1997, Romero Feris was ultimately indicted for embezzlement of public funds in 1999. He was sentenced to 7 years in prison in May, 2002.

The northeastern tip of Corrientes Province was chosen as the site for Yacyretá Dam following an agreement between President Juan Perón and Paraguayan President Alfredo Stroessner in 1974. Yacyretá, whose 20 year-long construction and US$11 billion cost far exceeded initial estimates, is one of the largest hydroelectric dams in the world. Currently, an agreement is being pursued with Paraguay which would allow reservoir expansion works that could double the facility's current installed electric capacity of 4,050 MW.

Source Link: wikipedia

Corrientes is located between two rivers: the Uruguay (east), Paraná (west and north), which form the natural boundaries of its territory. The low height of the coast of Paraná is the cause of frequent flooding, although the protective infrastructure has received a strong impetus to the growing devastation of 1982. Water resources are used for power generation in the hydroelectric dam Yacyreta.

The province of Corrientes region covers roughly the Guaranis, ancient inhabitants of the area, called Taragüí (lizard, by the abundance of them in the area). It is difficult to determine exactly when the data population of this territory by guaraníes nomads, but is likely to come to him, along the rivers in the middle of I millennium a. C., after the division that separated the speakers of Tupi Guarani ñe'engatu of themselves.

The primitive Corrientes were established along the coast of Paraná, semi-nomadic communities formed, that last well into the era colonial.4 maintained hostile relations with its inhabitants, the bellicose Charrua (Pampa), who lived in the province of Entre Rios and the Eastern Republic of Uruguay.
In December 1527, Sebastian Gaboto, Venetian navigator in the service of Spain, discovered the river Paraná and March 31 of 1528, the Paraguay river, being thus the first sighted the west coast of Corrientes.
When given the adelantazgo Pedro de Mendoza in the Region of the Rio de la Plata, by Capitulaciones held between him and the king of Spain, flows remained in the territories granted to it.

The city of Corrientes was founded by Juan Torres de Vera advance and Aragon with the help of Alonso de Vera y Aragón, called Tupi and Hernando Arias de Saavedra-Hernandarias on April 3, 1588. The front needed to do to comply with the surrender of his post, as way station between Asuncion, Paraguay, and Buenos Aires, the growth of the region was favored. Tower of Vera and Aragon did not remain in the new foundation, as it continued to travel to Spain for the ratification of his office. Is the common but erroneous assertion that the founder named the city as San Juan de Vera of the Seven Currents, the minutes of the foundation recorded just the city of Vera, expanded over time to honor the founder and patron of the then apocopation in its current form.
The initial settlers were 62 Spaniards and Creoles from Asunción, who joined 86 others who arrived in the city of Concepción de Buena Esperanza. The same movement that led to years of Santa Ana Huacas, Itatí and Saint Lucia, which were organized as villages whose inhabitants were Indians in the great majority of the local Amerindian population.

Many Jesuit missions were set in the present northeast of the province (then part of Misiones), where he developed an intense and peculiar work of evangelization. This was the true catalyst of Guarani society in the region, as the alliance of political leaders (the mburuvicha guazú) with the Society of Jesus won the temporary protection of the Crown of Spain from the pressures of the colonial hacienda, interested in submitting to a system of parcels, and looting of the Brazilian Bandeirantes. Not all tribes Guaranito benefited from this system, however, while a large number of guaraníes settled in the missions and retrajeron remained hostile to the most isolated and remote areas of the region. The population Guaranito resulted in much of the social fabric that was the basis for the current organization of the province, despite the expulsion of the Jesuits led to the depopulation and loss of eastern territory of the Missions, which will eventually fall into the hands of Brazilians.
When the Royal Charter by December 16 of 1617, the government initially assigned to Pedro de Mendoza was divided into two, the City of San Juan de Vera of the Seven Currents, was, along with others, in the jurisdiction of the Governor's River of silver.

In the eighteenth century, conflicts between the natural flows and the governorship of Buenos Aires, to which he belonged, were intense, were mainly due to refusal to perform military service against the inhabitants of other areas or the natives. In 1732 an uprising commoner rose up against the governor Bruno Mauricio de Zabala, taking the side of the community of Asuncion, was harshly suppressed by troops sent from the capital. 30 years later, Governor Pedro de Ceballos was faced with a similar situation, caused by the order of recruiting militia to open a path towards real Tucumán.
Retaliation from the central government included the relocation of the River Uruguay which developed commercial transport in the Paraná, which was a blow to the local economy based on shipbuilding, providing naval carpentry throughout the Viceroyalty and tissues for the provision of autoabastecimento and neighboring markets.

Governors of the Royal Ordinance of 28 January 1782, which amended the administrative organization of the Viceroyalty of the Rio de la Plata by creating the Governor's Intendencias made that flows are assigned to the municipality of Buenos Aires.

Own body is an organized militia, Hunters Corrientes, which during the English Invasions of 1806 and early 1807, assisted in the defense of Buenos Aires under the command of Juan José Fernández Blanco, assistant to the Third of Vizcaino. The body was removed after the failed coup of January 1, 1809 led by Martin de Álzaga.
The city of Corrientes, and endowed with a clear identity for the time of independence argentina, now allied with the province and Spanish Creoles of Buenos Aires, becoming part of the alliance of provinces which form the Republic of Argentina later in 1811 people correntino adhered firmly to the May Revolution sending Simón José García de Cossio as first deputy in the Primera Junta of Buenos Aires, about the same time received little liberating troops under the command of General Manuel Belgrano in voluntarily going to review them many young Corrientes.

An open forum meeting at the March 11 Corrientes 1814 Juan Bautista Mendez elected as governor of the province. On April 20 of that year, the Town Council declared the independence of the province under the federal system recognizing General Jose Gervasio Artigas as Protector of the Free Peoples.
Established as an autonomous province, and indeed, the Director of the State Supreme Gervasio Antonio de Posadas, by decree of September 10, 1814, available form the provinces of Entre Rios and Corrientes (this also with the peoples of missions including the theory Brazil current) separately from the Governor's Office of Buenos Aires and fixing their respective jurisdictions.
General José de San Martín, born in the village of Yapeyú located in the province of Corrientes, but at the time of his birth was part of the territory of the Guarani Missions of the Interior, where you can see the ruins of his birthplace and a museum in his memory. Also Sergeant Juan Bautista Cabral, who legend says that at the Battle of San Lorenzo gave his life for the general San Martin, was correntino; Cabral was born in a village called Salted, located 110 km southeast of the capital.

Current stood by the side artiguista in fighting that followed and was a member of the League of Free Peoples, headed by him; Corrientes representatives attended the 1815 Congress of the East, where the provinces of Banda Oriental, Córdoba, Corrientes, Entre Rios, Misiones and Santa Fe were declared independent of Spain and any other foreign power.

Between 1818 and 1819, the government of the province was conducted by Andres Guazurary, lieutenant of Artigas, flatly rejected by the local patrician Guarani origin, however Guazurary was a wise and enlightened governor. A defeat of Artigas, the provincial government remained in the hands of the Supreme entrerriano, Francisco Ramirez, who later proclaimed the Republic of Entre Rios, which also included the territory correntino. Evaristo Carriego would be the military commander of the Department of transient currents during the Republic period, which was founded on no fewer than 12 schools and conducted the first census of the postcolonial era. Fallen Ramirez in July 1821 for his disagreements with the Santa Fe Estanislao Lopez, who allied himself with the board porteño against it, an uprising deposed Carriego.

In open council was appointed governor of Ramon Atienza, who convened a Provincial Congress. It issued 11 December 1821 the Provisional Rules, Constitution Correntina first. The Provincial Congress appointed governor Juan José Fernández Blanco at the end of that year.

Following Fernández Blanco deal chair of the provincial government one of its key figures, Brigadier General Pedro Ferré. Ferré ensure the region's eastern province, lawlessness by the conflict with the Brazilians, who had come to the weapons, which ultimately gave way to the provincial territory, also signed peace with the chieftains Chaco, ending the system of reductions and promote the region's economy. His relationship with Buenos Aires, and governed by Juan Manuel de Rosas, serious conflicts, the centralism of Buenos Aires, no less in phase than during the preceding Federal Directory, which would result in 1839 the governor of Genaro Berón aliase Astrada was against the East Fructuoso Rivera Rosas. Defeat in Battle of Pago Largo would end this attempt, but would lead to a continuing conflict with Buenos Aires, which would continue the campaign of José María Paz and then on secondment from the Governor Virasoro Benjamin, son of Ferro, in ruling by Justo José de Urquiza. The Corrientes fought against Rosas in Caseros and weight would be a faction of the Confederation in Argentina.
During the War of the Triple Alliance territory was invaded by the Paraguayan troops.

For the Interstate Agreement signed in Buenos Aires on July 18, 1978, the provinces of Chaco and Corrientes settled the dispute for the possession of islands in the Parana River, defining its borders completely.

The prevailing climate is subtropical without dry season, with abundant rainfall and high temperatures with little daily or seasonal variations, especially in the northwest. The southern province has a climate more associated with temperate pampas.

Corrientes province is part of the Mesopotamia argentina and more broadly in the region known as the coastline. Province is a flat, with the exception of the area known as Tres Cerros (near the town of La Cruz), east of the province, where there are some minor elevations of the hill that stands out the Nazarene, the highest point of the province with 179 meters above sea level. To the west is a series of steps whose heights decrease to reach the river Paraná, south, confining with Entre Rios there is a low plateau: the Payubré covered by dense jungle until the end of s. XX.
The area of the Ibera marshes and ponds, covering one quarter of the provincial area, is a large depression in stroke volcanic soil, then covered by sediments of fluvial and eolian origin. The exact area occupied by wetlands varies with the height of the rivers in the region, which is connected with the underground, while the southern edge of the area is clearly defined by the natural boundary of the geology of an area of Entre-low hills that occupies the southern half of the province, northwest and northeast borders have no solution of continuity with the rest of the landscape. The geological origin of the zone is not clear. The most convincing hypothesis suggests that the Ibera basin would consist of the old bed of the Paraná River, which was diverted after the erosion made practicable the flow through the rocky bank of the falls Yacyreta-APIPA. Supports this theory the origin aluvionario soil, composed of layers of sand and silt on a bed of impermeable clay that prevents direct drainage of water. The circulation of these are produced through the Rivers Flow and Miriñay into the basins of the Paraná and Uruguay respectively. The frequent rains, especially during spring and autumn, the reset level of the marshes, which has shown tendencies to change in recent years.