This mod is been created by Apocalypse Riders !
It adds the Fox River State Penitentiary to the San Andreas map.
Look into the pictures to see the location of the prison.

Important : Install this mod on a clean version of GTA San Andreas, because if you install it with other mods, it might give problems, i'm not sure, just make a copy of a clean GTA San Andreas installation 

I uploaded a savegame wich will let you spawn in Fox River after loading. Read the readme correctly for installation.