Abismo Ouro Grosso, Alto Ribeira State Touristic Park

Abismo Ouro Grosso, also Gruta Ouro Grosso, is a 192-metre-deep shaft consisting of waterfalls and natural pools. It was created by the capture of surface rivers by carbonate rocks with subterranean drainage systems in an advanced stage of evolution. First explored by the German naturalist and spelunker Michel Le Bret in the 1970s, it is located at the Nucleo Ouro Grosso, within the borders of the Alto Ribeira Tourist State Park, in the municipality of Iporanga, 350 kilometres from Sao Paulo, Brazil. ()