10. San Quentin Prison
The oldest prison in California, having been founded in 1852. Despite the fact that the jail contains a gas chamber, lethal injection is the sole method of execution used there. Even with a big team of guards, violence is a constant problem in San Quentin.
A particularly serious incident happened in February 2006, when 100 inmates were injured as a result of racially motivated attacks. In addition, two detainees were murdered.
The prison is notorious for its bad circumstances, and according to a 2005 assessment, “it is our view that housing individuals there is harmful.”