evidence: A longstanding border dispute involving territory in the vicinity of Masoller exists between Uruguay and Brazil, although this has not harmed close diplomatic and economic relations between the two countries; Brazil and Uruguay have not actively asserted overt measures to reinforce their respective claims to the area such as by sending troops to the vicinity. The disputed area is called Rincón de Artigas (Portuguese: Rincão de Artigas), and the dispute arises from the fact that the treaty that delimited the Brazil-Uruguay border in 1851 determined that the border in that area would be a creek called Arroyo de la Invernada (Portuguese: Arroio da Invernada), but the two countries disagree on which actual stream is the so-named one.