Gruta Casa de Pedra

Gruta Casa de Pedra is a cave in the karstic region of the Alto Ribeira Tourist State Park, in the state of Sao Paulo, Brazil, between the towns of Apia and Iporanga. It is 2,930 meters long and has the world's largest cave mouth, which is 172 meters high. It's in the cave's penultimate hydrographic sub-basin, where the Maximiano stream enters for about 800 meters before flowing into the Iporanga River. Its name comes from the size of its portico, which is the largest in the world.

Gruta Casa de Pedra is part of a technical survey containing more details on the Ribeira valley cave system, which will be published as soon as data from other Brazilian caves is finalized, according to measurements taken in the 1960s, but contrary to the allegation that the actual size of the cave's entrance is 215 meters high. [2] Other measurements were taken in the cave using a range finder and a cyclometer in order to create a detailed cross-sectional profile of the cave entrance, which revealed that Gruta Casa de Pedra's cave mouth is 172 meters high, with a recalto on the roof of the entrance causing the height to rise to 175 meters,[2] making it the largest cave mouth in the world.

Location: inside Alto Ribeira Tourist State Park