Watch Behind Bars

La Mesa is a Mexican prison just over the US border. The inmates? Drug traffickers, rapists, cartel killers. They have tough times ahead. They hardly get to leave their cells. They sleep, eat, pee, all in a very confined space. Two square meters each - for up to eight inmates.

Armavir Prison is Armenia's declaration of war on gangster culture. Once, inmates in Armenian prisons fell into the hands of the "Thieves in Law"- a criminal brotherhood rejecting state authority and living by its own code. They control the prison and control drug trade and smuggling. Nobody knows their leaders, but their power is immense.

It's just a small prison, but a hard one. The Carcel Distrital in Bogotá, Colombia. Every day, the prison staff of 170 ensures stern discipline and order within the red brick walls. Their batons are loose and the inmates have to line up to be counted several times per day. Unannounced raids bring out a number of forbidden objects. This strict approach is necessary with nearly 1000 inmates.

South Cotabato Jail. One of the most overcrowded prisons in the world. Murderers, rapists, and drug dealers. The guilty and the innocent. All are behind bars together. In a jail designed for 600 prisoners, more than 2000 inmates are crammed into cells the size of shoe boxes.