Choeung Ek Killing Fields Cemetery

The Choeung Ek Killing Fields lie about a 30-minute tuk-tuk ride from central Phnom Penh, and are among the most sobering sites in Cambodia. This is where the Khmer Rouge carried out mass executions of the prisoners detained and tortured at Tuol Sleng - men, women and children were murdered here in appalling numbers.

The site is now a memorial and interpretive centre, explaining its significance and how the legacy of these events is confronted at both national and international levels. Informative English-speaking guides tell the grave and emotional history of the place; it is a weight best understood by seeing and feeling it for oneself.

At the centre of the grounds stands a memorial stupa filled with the skulls and bones of the dead. Before it, visitors can buy flowers or incense and remove their shoes to give a moment of silence and contemplation. It is best to visit in the cooler morning hours, particularly during the dry season from December to February.

Choeung Ek was the killing ground for prisoners held at the S-21 prison in Phnom Penh, and is the best known of the many such sites across Cambodia. The victims - adults, children and even infants - were murdered here in unthinkable ways as the Khmer Rouge pursued its violent vision of a remade society.

Decades later, the United Nations established a formal international tribunal to try those responsible. For the first time, the testimony of the few survivors was heard alongside that of the accused, though the legal process to hold the perpetrators to account stretched on for many years.