Lake Guinas is the larger of only two natural lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

s in Namibia

Namibia

Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...

. It is a sinkhole lake, created by a collapsing karst

Karst topography

Karst topography is a geologic formation shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite, but has also been documented for weathering resistant rocks like quartzite given the right conditions.Due to subterranean drainage, there...

 cave located 32 km north of Tsumeb

Tsumeb

Tsumeb is a city of 15,000 inhabitants and the largest town in Oshikoto region in northern Namibia. Tsumeb is the home of the world-famous Tsumeb mine, and the "gateway to the north" of Namibia. It is the closest town to the Etosha National Park...

 near the D3043 road.

Lake Guinas is home to Tilapia guinasana, a mouth-breeding species of fish that was endemic to this lake. It has later been introduced to Guinas' sister lake, Lake Otjikoto, as well as into few farm dams nearby. The claim that lake Guinas is indeed connected to lake Otjikoto by underground caves is frequently made but not proven as yet.

The lake is situated on private farmland but can be visited with the permission of the owner.