It is impossible to mention Cambodia without calling to mind the brutal regime of the Khmer Rouge. Two of the most visited places in Phnom Penh are Camp Cheoung Ek, one of many infamous Killing Fields sites, and Tuol Sleng Genocide Museum, a former high school that became a torture centre known as S-21.

This is the second time I have visited these two places. The experience is deeply disturbing but essential if one is to gain insight into Cambodia’s terrible past.  Camp Cheoung Ek lies 15 kilometres southwest of the city and was the burial site for those tortured and killed in S-21. In 1980, 129 mass graves were found here and 8,985 corpses unearthed. Today, a large stupa contains the bones and remnants of clothing as a memorial to the victims.

A visit to Tuol Sleng Genocide Museum is a harrowing experience. Located in a suburb of Phnom Penh, the school building is thought to have seen 20,000 citizens pass through its doors to be tortured and murdered by the Khmer Rouge.

On the ground floor, rooms with a single bed and leg irons where torture was carried out now envelop visitors in an eerie silence; on the upper floors claustrophobic numbered cells are stained with blood.

 In the courtyard, a makeshift gallows still stands.

One of the most haunting experiences, however, is looking at the thousands of black and white images of victims displayed on boards throughout the building. Like all regimes that have committed genocide, the Khmer Rouge was meticulous in documenting those it killed.

 More images can be seen in the Cambodia Gallery.