Caves in eastern and southeastern West Virginia form when groundwater dissolves limestone. West Virginia has at least 4,200 caves; Organ Cave (Greenbrier County) and Friars Hole (Greenbrier and Pocahontas counties) are the longest.

Caves protect unique animals such as bats and cave crickets.

Some are open for public tours, but due to safety concerns, never enter a cave without permission and or without an experienced spelunker as a guide.