The Missouri State Penitentiary operated from 1836 to 2004, making it one of the oldest penitentiaries west of the Mississippi, and it holds a grim distinction: Time magazine called it the bloodiest 47 acres in America. Today it operates as a museum and event venue, offering a range of tours from straightforward history walks through the cellblocks and execution chamber to evening ghost tours that lean into the building's dark reputation.
The stone cellblocks and guard towers are architecturally impressive in their grim way, and the history tour does a serious job of covering both the violence and the social history of American incarceration. Pretty Boy Floyd and James Earl Ray are among its famous former residents. Advance booking is strongly recommended, especially for weekend tours.