Acidic ground water (rain-water that has absorbed atmospheric carbon dioxide to form carbonic acid) dissolving the limestone as it flows through the joints & other discontinuities in the rock mass.
Yes, it's a small cave or cavern or artificial structure or excavation made to resemble a cave or cavern.
That is an easy one. It counts how far you made it into the dungeon.
The Cavern Club was made famous because the Beatles played there when they were first starting out. This was also the place where Brian Epstein first heard the band play.
I'll explore this cavern when I have a flashlight.
Cavern is a noun.
The suffix for cavern is -ous, as in cavernous.
Cavern of the Fear was created in 2002.
The Cavern Club was created in 1957.
Space Cavern was created in 1980.
Space Cavern happened in 2600.
Cavern Creatures was created in 1983.
Cavern Creatures happened in 1983.