The Kentucky State Penitentiary, also known as the "Castle on the Cumberland", is a maximum security and supermax prison with capacity for 856 prisoners located in Eddyville, Kentucky on Lake Barkley on the Cumberland River, about 4.8 kilometres from downtown Eddyville. It is managed by the Kentucky Department of Corrections. Completed in 1886, it is Kentucky's oldest prison facility and the only commonwealth-owned facility with supermax units.