Onmeetbarediepgat is one of the major
cave
A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...
s in the
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
formations in the district of
Bredasdorp
Bredasdorp is a town in the Southern Overberg region of the Western Cape, South Africa, and the main economic and service hub of that region. It lies on the northern edge of the Agulhas Plain, about south-east of Cape Town and north of Cape Agul ...
in the
Western Cape
The Western Cape is a province of South Africa, situated on the south-western coast of the country. It is the fourth largest of the nine provinces with an area of , and the third most populous, with an estimated 7 million inhabitants in 2020 ...
Province of
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
. The name in
Afrikaans
Afrikaans (, ) is a West Germanic language that evolved in the Dutch Cape Colony from the Dutch vernacular of Holland proper (i.e., the Hollandic dialect) used by Dutch, French, and German settlers and their enslaved people. Afrikaans gra ...
means "Immeasurably deep hole". The cave system is expressed at the surface as a
sinkhole
A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are locally also known as ''vrtače'' and shakeholes, and to openi ...
about 50 metres wide and 20 metres deep. The bottom is covered with limestone rubble. A small hole leads into a substantial cave system, which has been explored since the 1950s, mainly by cavers belonging to the South African Spelaeological Association (SASA). Entry to distant parts of the cave is hindered by
sumps.
Caves of South Africa
Landforms of the Western Cape
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