ADX Florence, located in Florence, Colorado, is a federal Supermax prison. Known as the Alcatraz of the Rockies, Supermax is home to over 400 of the most dangerous and violent offenders in the federal prison system. The Unabomber Ted Kaczynski, Oklahoma City bombing co-conspirator Terry Nichols, the Boston Marathon bomber Dzhokhar Tsarnaev and several other terrorists are serving time at the ADX.