Wabasha Street Caves Tour
St. Paul, Minnesota
These extensive caves, carved into a hillside in long-abandoned mining ventures, were sometimes used as a mushroom farm and sometimes served as a speakeasy. A gangland murder, similar to the St. Valentine's Day Massacre, reportedly took place in them. Tour guides point out the bullet holes.
Tipster Troy warns that visitors should only enter the Wabasha Street Caves with official guides (Those caves are inspected regularly). In 2010, three teens entered an unused and off-limits cave, started a fire, and died of carbon monoxide poisoning while exploring. Since 1988 there have been five previous deaths in the cave system, which extends for miles. The many entrances along the Mississippi River entice locals to attempt dangerous explorations, even as park officials have tried to seal up the holes. A plaque warns of the hazards.