Cave-In-Rock is a village in Hardin County, Illinois, United States. Its principal feature and attraction is nearby Cave-In-Rock, on the banks of the Ohio River. Cave-in-Rock was originally a stronghold for outlaws including; river pirates and highwaymen, Samuel Mason and James Ford, tavern owner/highwayman, Isaiah L. Potts, serial killers/bandits, the Harpe Brothers, counterfeiters, Philip Alston, Peter Alston, John Duff, Eson Bigsby, and the Sturdivant Gang, and the post-Civil War bandit, Logan Belt. The population was 346 at the 2000 census.