Bonito, Brazil
Gruta do Lago Azul Natural Monument (Blue Lake Cave) is a natural monument in Bonito, Mato Grosso do Sul, Brazil. It holds two caves with interesting but fragile calcareous formations, and has been listed as a protected area since 1978.
Listen to the audio guide for Gruta do Lago Azul Free on WIP — starts by itself when you arrive, even with the screen off