Illinois' Cave-In-Rock was once a naturally formed hive of scum and villainy.

Illinois’ Cave-In-Rock Was Once a Naturally Formed Hive of Scum and Villainy

Illinois’ Cave-In-Rock Was Once a Naturally Formed Hive of Scum and Villainy

Atlas Obscura
Your Guide to the World's Hidden Wonders
June 15 2015 11:00 AM

A Cave of Villainy on the Ohio River

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Located in an Illinois state park bearing its name, within a village that does as well, Cave-In-Rock is a fairly peaceful public park feature. But it has a storied history of gambling, prostitution, piracy, murder, and general villainy. 

The 55-foot-wide cave sits on the bank of the Ohio River and takes its name from the explorer who discovered it 1739, dubbing the natural shelter "caverne dans Le Roc." The cave features a fissure in the top which acts as a natural chimney, making it perfect for wilderness habitation.


Almost immediately after the cave was discovered, it became a wretched hive of scum and villainy. From around 1790, Cave-In-Rock was base camp for a group of river pirates who would ambush flatboats carrying cargo down the Ohio River. Pirates, bandits, fugitives, and murderers used the cave as a sort of hideout and hangout where they could scheme, gamble, drink, and even kill. People are said to have been forced off the cliff above the cave to their death.

Among the famed criminals said to have hidden out in the caves are the Harpe brothers, considered America's first serial killers due to a spate of murders they embarked on in 1798. There is even a local legend that Jesse James and his gang once took refuge there.

However the bad times could not last forever. In 1799 a group of justice-minded vigilantes known as "The Exterminators" raided the cave and the surrounding area, effectively destroying the ne'er-do-wells' hold on the site. More bandits moved into the space, but none stayed for long. In the mid-1800s the cave was even used as a church, while the small village that would come to be Cave-In-Rock was established nearby.

Today the cave sits empty in Cave-In-Rock State Park. Visitors willing to seek out the cave can still explore the space and kick back in the style of a bloodthirsty river pirate.

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Eric Grundhauser is a head writer and editor at Atlas Obscura. He lives in Brooklyn with his comic book collection. Follow him on Twitter.