Location: Marin County, Calif. Sitting on 275 acres of prime San Francisco Bay waterfront, the prison is said to be the most valuable in the world.
Ambiance: Founded in 1852, it's California's oldest prison. Despite the tony locale, with the state's only male death row and gas chamber (now used primarily for lethal injections), San Quentin is as tough as it gets in the Golden State.
Famous Guests: The prison serves as the current digs of nefarious wife and baby killer Scott Peterson, and is the former home of both Charles Manson and Robert F. Kennedy's assassin, Sirhan Sirhan.
Activities: Prisoners make furniture and mattresses, can study English as a second language or take a high school GED program, as well as participate in community service, eyeglass recycling and bicycle repair.
Staff: A staff of more than 1,700 workers keep 5,222 inmates in order.