Behind Bars: The World's Toughest Prisons

It is said that no one has ever managed to escape from Colony Eight, where over 800 prisoners are behind bars under maximum security conditions.

The pre-trial prison Urso Branco is one of the worst jails in all of Brazil. Riots have been taking place here almost every year since 2002.

The Correctional Institution for Women is the oldest and largest women's prison in the Philippines. Prisoners range from petty criminals to murderers.

Zenica—the biggest and toughest prison in Bosnia and Herzegovina—has survived all kinds of threats: rebellions, escape attempts and both world wars.

The few correction officers who work here risk their lives every day to keep its more than 1,000 prisoners inside, especially during daylight hours.