Brazil

Caving / Speleological Tours - More than 300 limestone caves can be found in the state parks of Petar, Intervales and Jacupiranga which form part of the Atlantic Rainforest South-East Reserves World Heritage Site in the south of São Paulo State.

The caves are part of an espactacular karst landscape, which was formed during million of years by the chemical dissolution of limestone. When the resultant of this reaction, a calcium bicarbonate (Ca(HCO3)2) solution, runs along the cave ceiling, it looses its velocity, forms drops, releases the excess carbon dioxide (CO2) and causes the much less soluble calcium carbonate (CaCo3) to be deposited. A stalactite is formed.

The drop which falls from the cave ceiling, still contains some calcium carbonate which is released when it hits the cave floor. A stalagmite is formed. Sometimes, stalactites and stalagmites grow together, forming a so - called column. These and many other speleothems are the main ecotouristic attractions while visiting a limestone cave.

See also: guided tours