Most of Namibia consists of old Precambrian and Cambrian basement rocks. This rocks contain several valuable rocks and ores. Most famous are the diamonds from Namibia, which are a base of the Namibian economy. The crystalline rocks are not soluble, but they contain abundant marble outcrops.
Probably the most famous cave of Namibia is the Drachenhauchloch (Dragons Breath Cave, Dragon’s Breath Cave), which contains the world's largest underground lake. It has a surface of 2.61 hectare. Arnhem Cave is the longest cave of Namibia and also the only tourist cave.
Histoplasmosis has not been recorded from any Namibian cave. Visitors should be very careful, not to introduce spores of the fungus into Namibia. If you come from countries with histoplasmosis, or visit Namibia after caving in such countries, please clean and sanitise all equipment before entering Namibian caves.