right in the centre of the capital, tuol sleng, also known as s21, was a high school that became a prison. inmates were stripped, suffocated, interrogated, beaten and electrocuted here. now it is a museum. foreign tourists from all over the world come here to learn. but you don't see many cambodians here. some of the local people i've spoken to say they don't want to be reminded of what happened here. there are thousands of pictures taken of each prisoner as they arrived. each of them would have had families, a life and this is the only way we can now remember them. over 12,000 people are estimated to have come through these doors. only a handful left again. i think of all the photographs, it is the ones where they are smiling which make me feel most sick because we now know what happened to them. they would have had some idea of what would happen to them. it just doesn't fit what's actually going on in this place, or what went on. they just look happy. thank you, lady, thank you. it is so good to see you. chun lei did survive s21. at 86 he is one of the last still alive. he comes back he