The Argentina–Brazil border is the line that limits the territories of the

Argentine Republic Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

and the

Federative Republic of Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

. It is approximately long. Starting at the confluence of Paraná and Iguaçu rivers, it passes through the

Iguaçu Falls Iguazú Falls or Iguaçu Falls ( , ; ; Tupi: Y Ûasu "big water") are waterfalls of the Iguazu River on the border of the Argentine province of Misiones and the Brazilian state of Paraná. Together, they make up the largest waterfall system ...

and follows the

thalweg In geography, hydrography, and fluvial geomorphology, a thalweg or talweg () is the line or curve of lowest elevation within a valley or watercourse. Normally only the horizontal position of the curve is considered (as viewed on a map); the c ...

of that river to the mouth of Santo Antônio River, then running upstream the course of this river until its source. From there the boundary runs by land until reaching the source of the Peperi-Guaçu River and from there along the channel of that river to its confluence with the

Uruguay River The Uruguay River ( ; ) 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 Mesopotamia from the other two countr ...

, then running downstream the course of the Uruguay to the mouth of river Quaraí. It was defined by the ''Treaty of 1898'' (which is based on an ), referred by

President of the United States The president of the United States (POTUS) is the head of state and head of government of the United States. The president directs the Federal government of the United States#Executive branch, executive branch of the Federal government of t ...

Grover Cleveland Stephen Grover Cleveland (March 18, 1837June 24, 1908) was the 22nd and 24th president of the United States, serving from 1885 to 1889 and from 1893 to 1897. He was the first U.S. president to serve nonconsecutive terms and the first Hist ...

, and is perfectly demarcated. The characterization work is in charge of the so-called "Joint Commission for Inspecting the Mark of the Brazil-Argentina" (created in 1970), which has deployed 310

boundary markers A boundary marker, border marker, boundary stone, or border stone is a robust physical marker that identifies the start of a land boundary or the change in a boundary, especially a change in direction of a boundary. There are several other t ...

. Its total length is by rivers and only by land.

References

1898 establishments in Argentina 1898 establishments in Brazil 1898 in international relations Borders of Argentina Borders of Brazil International borders {{Brazil-geo-stub