Mato Grosso do Sul region in Brazil (and especially the quiet town of Bonito) boasts many marvelous underground lakes: Gruta do Lago Azul, Gruta do Mimoso, Aquário Natural. The world famous "Gruta do Lago Azul” (Blue Lake Cave) is a natural monument whose interior is formed by stalactites, stalagmites and a huge and wonderful blue lake. The beauty of the lake is something impressive. The Blue Lake Cave has a big variety of geological formation but impresses mainly for the deep blue colored water of its inside lake.
