Top 10 most infamous prisons in the world – Nelson Mandela was locked in #5 for 27years (With Pictures)

2. Tower of London, England

The Tower of London is a historic castle on the north bank of the River Thames. The castle along with the neighboring Tower Bridge are among the most visited monuments in London and even in the entire world. The Tower of London served as a prison from 1100 till 1952, and was the most important royal prison in the country during medieval times. The former prison is now a UNESCO world heritage site, and is often mentioned as the most haunted building in England, haunted by the ghosts of previous prisoners