A super-maximum security (supermax) or administrative maximum (ADX) prison is a "control-unit" prison, or a unit within prisons, which represents the most secure level of custody in the prison systems of certain countries.
Its official name is the U.S. Penitentiary Administrative Maximum Facility, but everyone calls it "ADX" or " ADX Florence." The ADX in Florence, Colorado, is the one and only federal "Supermax" prison, home to the most dangerous criminals and escape-prone offenders in federal prison.
Colloquially known as ADX, it’s the only federal Supermax prison in the country, and no one has ever escaped the “Alcatraz of the Rockies.” Opened in November 1994, the facility sits on the outskirts of Florence, a small town in Fremont County (aka Colorado’s Correctional Capitol).
America's only federal supermax prison, which has housed criminals Joaquín "El Chapo" Guzmán, Dzhokhar Tsarnaev and Ramzi Yousef over the years, confines incarcerated persons to their cells for 23 hours daily.
The United States has one federal supermax prison and supermax-level facilities or housing units in at least 44 states. The single federal facility is ADX Florence in Colorado, operated by the Bureau of Prisons.
Supermax prison, correctional facility, or collection of separate housing units within a maximum-security prison, in the American prison system that is designed to house both inmates described as the most-hardened criminals and those who cannot be controlled through other means.
The Federal Supermax Prison in Colorado is a fortress of solitude, a place where some of the most notorious inmates in America’s history reside. Located in the town of Florence, this maximum-security facility is designed to house the most violent and high-risk prisoners, with a population of around 400 inmates who are considered too dangerous to be held in regular prisons.