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 (), 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 (), but the two countries disagree on which actual stream is the so-named one. So far, Rincão de Artigas is effectively under Brazilian control. The village of Masoller itself is in undisputed Uruguayan territory, just a few hundred metres from the largely unmarked and unimpeded
de facto international border. ==Population==