The Historic Pottawattamie County Jail, better known as the Squirrel Cage Jail in part because of its interior appearance, is one of three human rotary jails still in existence. The jail was designed to provide “maximum security with minimum jailer attention.” The jail is essentially a three-story cylinder with each level of the cylinder divided into small, pie-piece-shaped cells.

The patented design allowed one jailer to rotate the entire, three-story cylinder (and all its prisoners) around in a circle using just a hand crank. The jail held 63 prisoners who could not leave their cells unless their cell was cranked around to the doorway. Built in 1885 for about $30,000, safety concerns eventually led the jail to be modified away from the original rotary configuration. The county quit using the jail altogether in the 1960s. Today the structure is a historic museum open to public tours.