A cave or cavern.
vent
The Sarawak Chamber is the largest known cave chamber in the world. The Sarawak Chamber is a cave that is located underground in the country of Malaysia.
A magma chamber.
Magma Chamber: underground pocket of molten rock
A magma chamber is a large underground pool of molten rock found beneath the surface of the Earth. The molten rock in such a chamber is under great pressure, and given enough time, that pressure can gradually fracture the rock around it creating outlets for the magma. If it finds a way to the surface, then the result will be a volcanic eruption; consequently many volcanoes are situated over magma chambers. Magma chambers are hard to detect, and most of the known ones are therefore close to the surface of the Earth, commonly between 1 km and 10 km under the surface. In geological terms this is extremely close to the surface, although in human terms it is considerably deep underground.
underground
calf
A cave or cavern.
Kim Kardashian
its a subterranean chamber ; a subterranean chamber is a underground room used to confuse robbers
Sarawak Chamber is largest underground chamber in the world by area. It is in Borneo.
Underground Chamber was created on 2011-08-17.
A cavern is an underground chamber formed by erosion
The Sarawak Chamber is the largest known cave chamber in the world. The Sarawak Chamber is a cave that is located underground in the country of Malaysia.
A magma chamber.
This is called a lava tube.
A subterranean chamber is a room or open space that is underground.
Magma Chamber: underground pocket of molten rock