It was formed from a sinkhole that was created by a collapsing karst, a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum, cave. The lakes diameter is 332 feet and its depth is around 300 feet.
The lake was used as a dumping ground for the German Schutztruppe, the colonial troops in the African territories of the German colonial empire from the late 19th century to 1918, during World War I. They disposed of their war materials before surrendering to the South Africa and British troops.
There are cannons, firearms, ammunition and possibly a sealed safe with 6 million gold marks, yet to be found. The tourism papers report that “the lake tapers into a lateral cave system making it impossible to determine its exact depth,
estimated to be in excess of 142 meters” (466 feet). Some items have sank to these crazy depth and yet to be located. You can dive and see some recovered items displayed on a shallow shelf.
If you don’t want to get wet, then visit the Tsumeb Museum. There is also a unsubstantiated claim that Otjikoto Lake is connected by a cave system to its sister Lake Ngami.