Uruguay River in the context of "Misiones Province"

The Río de la Plata basin (Spanish: Cuenca del Plata, Portuguese: Bacia do Prata), more often called the River Plate basin in scholarly writings, sometimes called the Platine basin or Platine region, is the 3,170,000-square-kilometre (1,220,000 sq mi) hydrographical area in South America that drains to the Río de la Plata. It includes areas of southeastern Bolivia, southern and central Brazil, the entire country of Paraguay, most of Uruguay, and northern Argentina. Making up about one fourth of the continent's surface, it is the second largest drainage basin in South America (after the Amazon basin) and one of the largest in the world.

The main rivers of the La Plata basin are the Paraná River, the Paraguay River (the Paraná's main tributary), and the Uruguay River.

The Paraná River (Portuguese: Rio Paraná [ˈʁi.u paɾaˈna] ; Spanish: Río Paraná [ˈri.o paɾaˈna] ; Guarani: Ysyry Parana) is a river in south-central South America, running through Brazil, Paraguay, and Argentina for some 4,880 kilometres (3,030 mi). Among South American rivers, it is second in length only to the Amazon River. It merges with the Paraguay River and then farther downstream with the Uruguay River to form the Río de la Plata and empties into the Atlantic Ocean.

The first European to go up the Paraná River was the Venetian explorer Sebastian Cabot, in 1526, while working for Spain.

The Río de la Plata (Spanish pronunciation: [ˈri.o ðe la ˈplata] ; lit. 'River of Silver'), also called the River Plate or La Plata River in English, is the estuary formed by the confluence of the Uruguay River and the Paraná River at Punta Gorda. It empties into the Atlantic Ocean and forms a funnel-shaped indentation on the southeastern coastline of South America. Depending on the geographer, the Río de la Plata may be considered a river, an estuary, a gulf, or a marginal sea. If considered a river, it is the widest in the world, with a maximum width of 220 kilometres (140 mi).

The river is about 290 kilometres (180 mi) long and widens from about 2 kilometres (1.2 mi) at its source to about 220 kilometres (140 mi) at its mouth. It forms part of the border between Argentina and Uruguay. The name Río de la Plata is also used to refer to the populations along the estuary, especially the main port cities of Buenos Aires and Montevideo, where Rioplatense Spanish is spoken and tango culture developed. The coasts of the river are the most densely populated areas of Uruguay and Argentina.

Punta Gorda is a landform in Colonia Department, Uruguay.

According to the Treaty between Uruguay and Argentina concerning the Rio de la Plata and the Corresponding Maritime Boundary, it marks the mouths of the Uruguay River on the Río de la Plata.

The Argentina–Uruguay border is a line of 579 km marked by the Uruguay River, and is the border between Argentina and Uruguay. It starts in a triple border Argentina-Uruguay-Brazil, at the mouth of the Quaraí River in the Uruguay. The course follows the Uruguay river, passing west of the Uruguayan departments of Artigas, Salto, Paysandu, Rio Negro, Soriano and Colonia and the Argentine provinces of Corrientes, Entre Rios and Buenos Aires, until the confluence of the Uruguay and the Paraná rivers into the Rio de la Plata.

The Mesopotamia or Región Mesopotámica is the humid and verdant area of northeast Argentina, comprising the provinces of Misiones, Entre Ríos, and Corrientes. The landscape and its characteristics are dominated by two rivers: the Paraná and the Uruguay.

When Spanish settlers came to the area, the two parallel rivers and the lush area between them drew comparisons to Mesopotamia (Greek: Μεσοποταμία "land between rivers") in modern-day Iraq, and it was decided that the Argentine region be named after the Iraqi region. The region shares many of its ecological features with neighboring regions of Argentina and with parts of Brazil, Paraguay, and Uruguay.

Artigas Department (Spanish: Departamento de Artigas) is the northernmost department of Uruguay. Its capital is the city of Artigas, which borders the Brazilian city of Quaraí. Artigas Department has an area of 11,928 square kilometres (4,605 sq mi), making it the fifth largest in the country. The population is 77,487 inhabitants, according to the 2023 census.

It is bordered on the north and east by Brazil, from which it is separated by the Cuareim River. To the south, Artigas Department borders on Salto Department, and to the west is Argentina, from which it is separated by the Uruguay River. Artigas is the only Uruguayan department that borders two other countries.