Phnom Trung Bat detention and execution center was known to Documentation Center of Cambodia (DC-Cam) since 1998 as an infamous site for short-term detention and execution. According to Chem Sao Da, male, 56, who is a former Khmer Rouge soldier from 1973-1977, there are at least three main mass graves in the area. The two previously known graves are about 10 by 10 meter wide and 3 meter deep. In these pits, semi-conscious bodies were thrown into burning rice husk. Ashes were later used as fertilizer for the rice field. Today fragments of charred bones from these pits are stored in a memorial. In 1979 and 1980 many people collected gold from remains in these two pits. According to Kak Kay, male, 40, there is also a small grave to the south of these two pits which have nine bodies which were killed in late 1978. The Khmer Rouge also dug up a new larger pit of about 18 meter wide, 40 meter long and 3 meter deep. But this new pit was never used when the Vietnamese arrived in 1979.

According to villagers, the newly discovered grave was an old well which the Khmer Rouge expanded to about 4 by 4 meter wide and 10 meter deep. The Khmer Rouge made it this wide to prevent anyone who was not killed from climbing up by pushing against the sides of the well. After dropping 15 to 20 bodies, the Khmer Rouge covered them with a layer of rock and dirt. This is revealed during excavation of the pit. Some of the bones in this pit are still not excavated. Because the bodies were deeply buried and compacted, after thirty years, the villagers said they still produce stench.

During the Khmer Rouge, the current village named Dor Dantrey, Kampong Thkov commune, Kralanh district, was not inhabited by villagers. Many houses were dismantled but only three were kept as detention and administrative buildings for the prison. Today these houses are occupied by relatives of pre-Khmer Rouge owners. The house of Chhaom Saron, male, was used as detention center. When he arrived at the house in 1979, he found shackles, iron bars and some robes. The house belongs to his parents in Lon Nol regime. In 1979 he lived in it with two brothers and a sister. Now he lives with his wife and children.

Five meter to the south is a house used by the Khmer Rouge as accommodation for its prison staff. The close proximity of the house was ideal for guarding the prisoners inside the detention house. Today this house is occupied by Che Sek, male, 80, who has returned since 1979.

To the east of both house is the third house used by the Khmer Rouge as administrative center storing documents and belongings of prisoners. It was also used as accommodation for prison chief. Current owner of this house is Sari Mom, female, 52, whose father built the house in 1962. She said when she first arrived at the house in 1979, she found lots of clothes and sleeping mats. She collected them and burnt at the back of the house. All three houses are large and still in good condition.

Just south of the newly discovered pit is the house of landowner named Chea Hing.