Tuol Sleng Genocide Museum

What to See at Tuol Sleng

The Original Classrooms

Tuol Sleng was a high school (Lycée Tuol Svay Prey) before the Khmer Rouge converted it into Security Prison 21 in 1975. Many classrooms remain largely as they were left — some still divided into the crude brick cells used to hold prisoners, others left open with rows of iron bed frames and shackles.

The Photographic Archive

The Khmer Rouge meticulously photographed nearly every prisoner who passed through S-21 — an estimated 12,000 to 20,000 people over four years. Building D displays room after room of these photographs, an overwhelming and deliberately unflinching record.

Survivor Testimony

Only a small number of S-21 prisoners are known to have survived. Several, including the painter Vann Nath and mechanic Chum Mey, gave testimony and created artwork depicting conditions inside — some of which is displayed on site, along with their personal accounts.

UNESCO World Heritage Status

In July 2025, UNESCO inscribed Tuol Sleng as part of “Cambodian Memorial Sites: From Centres of Repression to Places of Peace and Reflection” — a serial listing alongside Choeung Ek and the former M-13 prison in Kampong Speu. It was Cambodia’s fifth World Heritage Site and its first to document the Khmer Rouge era directly.

How to Get to Tuol Sleng

Tuol Sleng is in central Phnom Penh, about 15 minutes by tuk-tuk from the riverfront.

• Tuk-tuk: $3–5 from most central hotels
• Walking: Possible from nearby guesthouses, 20–30 minutes from the riverfront
• Combine with: Choeung Ek Killing Fields, 15km outside the city — most visitors do both on the same morning

Best Time to Visit

Visit in the morning, both for lighter crowds and so you have time afterward to process what you’ve seen before moving on to anything else. Many travelers find it emotionally heavy — that’s an appropriate response, not something to rush past.

Practical Information

• $5 entry, with an optional $3 audio guide (highly recommended — narrated by survivors and historians)
• Photography is permitted in most areas; be mindful and respectful, particularly around photographs of victims
• Allow time to sit afterward — many visitors find a quiet coffee nearby helpful before continuing their day
• Children under 10 may find the content distressing; use discretion

Nearby Attractions

Choeung Ek Killing Fields, where many S-21 prisoners were ultimately taken, sits 15km south of the city and is the natural pairing for understanding the full arc of this history.