A show cave—also called tourist cave, public cave, and, in the United States, commercial cave—is a cave which has been made accessible to the public for guided visits.
Trail stairs in Mammoth Cave, United States
An artificial complex illumination in Reed Flute Cave, China
Color-highlighted ice in Kungur Ice Cave, Russia
Lighting in Manjanggul lava tube, Jeju, South Korea
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 caves, rock shelters, and grottos, that extend a relatively short distance into the rock and they are called exogene caves. Caves which extend further underground than the opening is wide are called endogene caves.
Lechuguilla Cave, New Mexico, United States
Speleothems in Hall of the Mountain King of Ogof Craig a Ffynnon, a solutional cave in South Wales.
Exploring a lava tube in Hawaii.
Painted Cave, a large sea cave, Santa Cruz Island, California