Officials have dismantled a map of Cambodia made out of skulls - a key icon of Khmer Rouge atrocities.
Buddhist monks chanted and prayed for the souls of the 300 victims whose remains became part of the map.
It has been displayed publicly since 1979 as a testament to the regime's brutality.
The map, held together by wire, was taken apart after the Buddhist ceremony and the human remains placed in a wooden case enclosed by glass.
Hundreds of thousands of Cambodian and foreign visitors to the Tuol Sleng Genocide Museum had viewed the 129 sq ft wall installation of skulls and bones. A Buddhist shrine will be erected at the site.
Chey Sopheara, director of the museum, said natural decay of the skulls made it clear it was time to dismantle the map.
He said: "By removing the skulls, we want to end the fear visitors have while visiting the museum."
The museum is located at a Phnom Penh school which the Khmer Rouge used as its chief prison and torture centre, known as S-21, or security office 21.
An estimated 1.7 million Cambodians died during the 1975-79 rule of the radical Maoists due to disease, starvation, overwork and execution. Leader Pol Pot died in 1998 but many of his top lieutenants live freely in Cambodia after reaching defection deals with Prime Minister Hun Sen's government.
The grim site was preserved by the conquering Vietnamese army that deposed the Khmer Rouge and occupied Cambodia for 10 years until 1989.