Choeung Ek, the site of a former orchard and Chinese graveyard about 17km south of Phnom Penh, Cambodia, is the best-known of the sites known as The Killing Fields, where the Khmer Rouge regime executed about 17,000 people between 1975 and 1979. Mass graves containing 8,895 bodies were discovered at Choeung Ek after the fall of the Khmer Rouge regime. Many of the dead were former inmates in the Tuol Sleng prison.

Today, Choeung Ek is a memorial, marked by a Buddhist stupa. The stupa has acrylic glass sides and is filled with more than 5,000 human skulls. Some of the lower levels are opened during the day so that the skulls can be seen directly. Many have been shattered or smashed in.

Tourists are encouraged by the current Cambodian government to visit Choeung Ek. Apart from the stupa, there are pits from which the bodies were exhumed. Human bones still litter the site.

On May 3, 2005, the Municipality of Phnom Penh announced that they had entered into a 30-year agreement with JC Royal Co. to develop the memorial at Choeung Ek. As part of the agreement, they are not to disturb the remains still present in the field.

The film The Killing Fields is a dramatized portrayal of events like those that took place at Choeung Ek.