Missouri State Penitentiary
The Missouri State Penitentiary is one of the most notorious prisons in the United States. It is known for its harsh conditions and high rate of inmate mortality. In 2001, it became the first prison in the United States to be certified as a Level III security prison by the U.S. Department of Homeland Security. The prison is also home to the nation's second-highest number of inmates, with more than 3,000 inmates.