 Chuy is one of the easternmost settlements in Uruguay, separated from Brazil by the Chuí Stream.The Chui rises in a small swamp in the sandy coastal plains of far southern state of Rio Grande do Sul, Brazil, runs initially southward, then turns east before flowing into the Atlantic Ocean.The Chui is only a few tens of kilometres long and its water volume is unimpressive; indeed, this is why it is called an "arroio" or "arroyo", a stream rather than a river.