The Killing Fields are a number of sites in Cambodia where collectively more than a million people were killed and buried by the Khmer Rouge regime during its rule of the country from 1975 to 1979, immediately after the end of the Cambodian Civil War. The mass killings are widely regarded as part of a broad state-sponsored genocide.
Analysis of 20,000 mass grave sites by the DC-Cam Mapping Program and Yale University indicates at least 1,386,734 victims of execution. Estimates of the total deaths resulting from Khmer Rouge policies, including death from disease and starvation, range from 1.7 to 2.5 million out of a 1975 population of roughly 8 million. In 1979, Vietnam invaded Democratic Kampuchea and toppled the Khmer Rouge regime, an act that is viewed as having ended the genocide.
Wikipedia https://en.wikipedia.org/wiki/Killing_Fields
Address (Unnamed Road), Cambodia
Coordinates 11°29'3.198" N 104°54'7.959" E