A school converted into Cambodia's most important prison in 1975. More than 14,000 people were tortured here before being killed at the killing fields; only 8 prisoners made it out alive. The museum is easily accessible and a must-see for everyone interested in Cambodia's horrific past. The infamous "skull map" has been dismantled, although there are still skulls stacked in cabinets, implements of torture and disturbing photographs of people dying. For an introduction and further reading, try David Chandler's Voices from S-21 (ISBN 0520222474). Documentary movie S-21 can be purchased in Phnom Penh for USD1.50-2. There is also a short movie screening featuring some survivors that plays at 09:30 upstairs in the far building. A hefty slice of your Tuol Sleng entrance fee will go into the pocket of the museum's director, who is the son of the responsible government minister. (This is perhaps the main reason the museum is in rather shabby condition, and the displays so unimaginative.) And a warning to those who patronize the souvenir shop. Don't get conned into buying some vintage Rolex, Patek Philippe, or Omega watches. They are fakes and are worthless. The owner is very convincing and will tell you that it is a collection from her husband. Instead, right across from the museum (No 54 & 56, St 113, Phnom Penh is a little shop called CHA (http://www3.online.com.kh/users/wthanchashop) that sells inexpensive handmade goods that are made by women disabled from polio and land mines. If you ask, you will also be able to tour the shop, meeting the female workers and seeing where they study English.