The maximum-security prison ADX Florence, located near Florence, Colorado, has a reputation as one of the worst prisons in the world.
Its construction was preceded by an incident that occurred in October 1983, when two prisoners managed to kill their guards.
This is how the idea of creating a correctional facility where uncontrolled prisoners would be isolated from other inmates and guards was born, and in 1994 Florence Prison opened its doors.
There are currently about 430 prisoners here, all of them men, each assigned to one of six security levels.
Most of them are kept in solitary confinement for at least 23 hours a day in cells measuring 2.1 by 3.7 meters. The window, measuring 10 by 120 cm, is positioned in such a way that the prisoner can see only the sky and the roof above the window.
Each room is equipped with steel doors and bars, and almost the entire interior is made of cast concrete, including the table, chair and bunk.
There is also a toilet that shuts off if it gets clogged, a shower with a timer to prevent flooding, and a sink without a faucet.
Cells may also be equipped with electric lighting, a polished steel mirror bolted to the wall, a radio and a television.
According to a former prison governor, it represents "a cleaner version of Hell."
