
Much has been written about ADX Florence, America's highest security prison. There are many prisoners there - from a tortured prisoner who ate his own finger, to a cartel leader who was brutally murdered by his comrades.
Drug lord Joaquin "El Chapo" Guzman has twice escaped from maximum security prisons, but for the past four years he has been locked up in a federal prison known as "Alcatraz of the Rocks."
No one has escaped or escaped ADX Florence in Colorado, which a former manager described as "worse than death."
El Chapo, who led Mexico's Sinaloa cartel, is serving a life sentence for accessory to murder and dozens of drug-related charges. Earlier this year, in a letter obtained by CBS News, he described his "psychological torture" in that prison and pleaded that his wife and daughters be allowed to visit him.
The 66-year-old also asked Mexican President Andres Manuel Lopez Obrador to extradite him back to his country because he is serving a miserable time in a US prison. This particular prison opened in 1995 and was originally built to isolate the most violent and cruel inmates, often murderers and terrorists, in a way that would keep everyone safe.
The idea for ADX Florence came after members of the neo-Nazi Ariane Brotherhood gang, Thomas Silverstein and Clayton Fountain, stabbed two police officers to death in a United States prison in 1983.
12 large towers surround and control the entire prison. The IEVP houses up to 490 inmates who live in 7 by 12 concrete cells. According to a Prison Observatory report, the cells also have their own showers to prevent inmates from touching each other.
Even during visits they are kept separate from friends and family and must interact with them through a glass screen.
The conditions were sharply criticized by Amnesty International's Americas director, Erika Guevara-Rosas, who said: “At some point we have to talk about the devastating impact that long periods of solitary confinement can have on a prisoner's mental and physical health. Such harsh treatment as a daily practice violates international law."
It is worth noting that in 2012 a lawsuit was filed against the US Bureau of Prisons after inmates were diagnosed as insane during their stay at ADX Florence.
While the prison was designed with security in mind, Mexican gang leader Manual Torrez died inside the prison in 2005 after being assaulted in the yard by inmates, who left him with 18 broken ribs and a fractured skull.
Three years ago, Britain refused to extradite WikiLeaks founder Julian Assange to ADX Florence, citing the risks of isolation as a factor. However, a number of British nationals are currently in prison, including ISIS Beatles member Alexandra Amon Kotei, known as Jihadi George.