Killing Fields of Cheung Ek is situated 15 kilometers south-west of Phnom Penh and made famous by the film of the same name "Killing Field". it was a place where more than 17,000 civilians were killed and buried in mass graves; many of them transported here after detention and torture in Toul Sleng. This place is a chilling reminder of the brutalities of the genocidal Khmer Rouge regime. In the center of the area is a 17 story glass stupa which houses 8000 skulls exhumed from mass graves. Open daily.Note: Both Tuol Sleng Museum and the Killing Fields exhibits may be disturbing for some and aren't suitable for younger children and adults who are easily shocked.