Unusually for a Spanish-s
Unusually for a Spanish-speaking South American nation, this country is less than fifty percent Catholic. Part of this country's border with Brazil runs through Lake Mirim, and this country is itself bisected east to west by the Rio Negro. Its capital sits on the north side of the estuary separating it from (*) Argentina, the Rio de la Plata. For 10 points, identify this country in the southeastern part of South America, whose capital has a name meaning "I see a mountain," Montevideo.
Unusually for a Spanish-speaking South American nation, this country is less than fifty percent Catholic.
Oriental Republic of {Uruguay} [or Republica Oriental del {Uruguay}]