Between 1975 and 1978 about 17,000 men, women, children and infants who had been detained and tortured at S-21 were transported to the extermination camp of Choeung Ek. They were often bludgeoned to death to avoid wasting precious bullets.
The remains of 8985 people, many of whom were bound and blindfolded, were exhumed in 1980 from mass graves in this one-time longan orchard; 43 of the 129 communal graves here have been left untouched. Fragments of human bone and bits of cloth are scattered around the disinterred pits. More than 8000 skulls, arranged by sex and age, are visible behind the clear glass panels of the Memorial Stupa, which was erected in 1988. It is a peaceful place today, masking the horrors that unfolded here less than three decades ago.
Admission to the Killing Fields includes an excellent audio tour, available in several languages. Introduced in 2011, the tour includes stories by those who survived the Khmer Rouge, plus a chilling account by Choeung Ek guard and executioner Him Huy about some of the techniques they used to kill innocent prisoners and defenceless women and children.
There is a museum here with some interesting information on the Khmer Rouge leadership and the ongoing trial. A memorial ceremony is held annually at Choeung Ek on 9 May.
To get to the Killing Fields of Choeung Ek, take Monireth Blvd southwest out of the city. The site is well signposted in English about 7.5km from the bridge near St 271.