The Killing Fields (Khmer: វាលពិឃាត viel pi-kʰiet) are a number of sites in Cambodia
where large numbers of people were killed and buried by the communist Khmer Rouge regime, during its rule of the country from 1975 to 1979, immediately after the end of the Cambodian Civil War (1970–1975).
Analysis of 20,000 mass grave sites by the DC-Cam Mapping Program and Yale University indicate at least 1,386,734 victims of execution. Estimates of the total number of deaths resulting from Khmer Rouge policies, including disease and starvation, range from 1.7 to 2.5 million out of a 1975 population of roughly 8 million. In 1979, communist Vietnam
invaded Democratic Kampuchea and toppled the Khmer Rouge regime.
The best known monument of the Killing Fields is at the village of Choeung Ek
. Today, it is the site of a Buddhist memorial to the victims, and Tuol Sleng has a museum commemorating the genocide. The memorial park at Choeung Ek has been built around the mass graves of many thousands of victims, most of whom were executed after they had been transported from the S-21 Prison in Phnom Penh
The utmost respect is given to the victims of the massacres through signs and tribute sections throughout the park. Many dozens of mass graves are visible above ground, many which have not been excavated yet. Commonly, bones and clothing surface after heavy rainfalls due to the large number of bodies still buried in shallow mass graves. It is not uncommon to run across the bones or teeth of the victims scattered on the surface as one tours the memorial park. If these are found, visitors are asked to notify a memorial park officer or guide.