Gruta Casa de Pedra, Xitué Ecological Station

Gruta Casa de Pedra is a cave located in the karstic region of the Alto Ribeira Tourist State Park, between the municipalities of Apiaí and Iporanga, to the south of the State of Sao Paulo, Brazil. It is 2,930 meters long and features the largest cave mouth in the world, measuring 172 meters high. It is located in the final portion of the hydrographic sub-basin of the Maximiano stream which enters the cave for about 800 meters and flows into the Iporanga River. Its name derives from the size of its portico, recognized as the world's largest. ()