In the state with the highest number of caves, some draw visitors every October for dank, dark tours and other seasonally ...

Plenty of outdoor activities await visitors in Gregg Township, including cavern tours, hiking, biking, fishing and more.

Launch your boat into the Ohio River or explore a 55-foot cave with fascinating pirate history in this state park in southeastern Illinois.

The stability of underground water-sealed oil storage caverns is of great importance for safe excavation and operation. To analyze the scope of the failure zone and underground cavern stability ...