The Brazil–Uruguay border is a strip of land located south of the southern Brazilian state of

Rio Grande do Sul Rio Grande do Sul (, , ; "Great River of the South") is a Federative units of Brazil, state in the South Region, Brazil, southern region of Brazil. It is the Federative_units_of_Brazil#List, fifth-most-populous state and the List of Brazilian st ...

. It stretches for 985 km from the triple border Brazil-Argentina-Uruguay west to the mouth of Arroyo Chuí, the southernmost point in Brazil. The western section of the border is marked by

Quaraí River Quarai is a Brazilian municipality located near the border with Uruguay on the Rio Quaraí. The population is 22,607 (2020 est.) in an area of 3,147.63 km2, making it one of the largest municipalities in the state. Its elevation is 112 m. It ...

, a tributary of the

Uruguay River The Uruguay River ( es, Río Uruguay, ; pt, Rio Uruguai, ) is a major river in South America. It flows from north to south and forms parts of the boundaries of Brazil, Argentina, and Uruguay, separating some of the Argentine provinces of La M ...

and the "coxilhas of Santana." To the east, its border is marked by the

Jaguarão River The Jaguarão or Yaguarón River ( pt, Rio Jaguarão, es, Río Yaguarón) is a Brazilian and Uruguayan river. It forms the border between Uruguay and Rio Grande do Sul state in southernmost Brazil. The river originates in Serras de Sudeste (South ...

that flows into the

Lagoa Mirim Lagoon Mirim (Portuguese, ) or Merín (Spanish, ) is a large estuarine lagoon which extends from southern Rio Grande do Sul state in Brazil into eastern Uruguay. Lagoa Mirim is separated from the Atlantic Ocean by a sandy, partially barren isth ...

. The border then runs from southern portion of this lagoon to the Chui. There are two disputed areas on the border between Brazil and Uruguay, which were the Brazilian Island and the Corner of Artigas (interfluve between the Quaraí River and the Arroyo Invernada). The two areas are administered by Brazil, yet are claimed for decades by Uruguay.

References

Borders of Brazil Borders of Uruguay International borders {{Uruguay-geo-stub