Most of Namibia consists of old Precambrian and Cambrian basement rocks. These 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 ha. As it is not open to tourists, we have not listed this cave, unlike the next. Arnhem Cave is the longest cave of Namibia and also one the two tourist caves.
Histoplasmosis has not been recorded from any Namibian cave, which is extraordinary as it occurs in the surrounding countries. 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.