Barra do Quarai (also Quarahim in archaic Portuguese spelling) is a Brazilian municipality located near the border with Uruguay (on the Rio Quaraí) and Argentina on the Uruguay River. The town became the westernmost city in the state of Rio Grande do Sul and in all Southern Brazil when it was separated from the municipality of Uruguaiana on December 28, 1995. It has a population of only 3,878 (2008). Its elevation is 35 m. It has an area of 1,056.146 km². It is located 717 km west of the state capital of Porto Alegre, and roughly the same distance northwest of Montevideo, Uruguay.