Tuol Sleng, or S-21 Prison, in Phnom Penh is an open wound for many Cambodians. My wife, Kulikar, shivers at its mention. Her uncle, Ang Choubee, was incarcerated there, tortured and executed.

Kulikar flipped through Choubee’s folder, scanning the record of his arrest and execution, and broke down in tears. All that remained of her uncle was the mangled frame of his spectacles, a telling symbol of the communist regime in the Seventies that targeted intellectuals.

Nothing prepares you for an encounter with Tuol Sleng Genocide Museum, the original Khmer Rouge security prison: the rusty manacles spattered with the stains of suffering; the graphic photos of the last victims bludgeoned to death. This is a walk on the dark side of humanity.

Wandering through room after room of black-and-white photographs of the anonymous victims of a revolution, some faces are defiant, some terrified, while others are bemused. All look imploringly at their audience; they seem silently to utter the same question: why?

Haunting images implant themselves in the mind. A young woman, Chan Kim Srung, holds her newborn baby. They were “smashed” soon after May 14, 1978. A popular Khmer Rouge slogan was to “pull the roots when cutting the weeds”.

It’s hard to imagine this place, which was built as a high school, as a playground. There are a few clues in the courtyard, including some climbing bars, but our guide, Chamreoun, soon shatters any illusions of normali-ty. “Here is where they tied the prisoners upside down and dumped their heads in jars of water,” he tells us.

One of the rooms is lined with primitive paintings depicting the brutal forms of punishment meted out for disobeying the rules. As many as 17,000 prisoners passed through the gates of this prison and were later executed at the killing fields of Choeung Ek. Driving out towards the killing fields, it is almost impossible to make sense of the violence unleashed in this indolent land, to square the heavenly vision of rural Cambodia today with the hell of the past.

Prisoners arrived at Choeung Ek under the cover of darkness and were executed with hoes and spades to save precious bullets. Many of the mass graves remain undisturbed, fragments of bone poking through the baked earth. Clothing fragments are mixed into the soil as if the ground opened up and swallowed the living. The remains of 8,985 bodies that were exhumed are on display in a memorial stupa. We burn incense to remember them.

The killing fields of Choeung Ek were one of hundreds of mass grave sites scattered throughout the country. In Battambang province in the west of the country there were widespread killings. The holy mountain of Phnom Sampeau is littered with shrines and stupas.

This brutal civil war rumbled on until 1998. After 30 years of turmoil, if any country has a shot at making a success of its history, drawing in visitors to teach them vital lessons about its terrible past, surely it is Cambodia.

But it’s not just “war tourism” that is bringing people to the country. Angkor has a spectacular collection of temples, the south coast conceals tropical beaches and the forests of northern Cambodia are home to rare wildlife and dramatic waterfalls.

However, more than its culture and nature, the Cambodian people are the national treasure. The Khmers may have been to hell and back, but somehow they returned with a smile.

As we cruise down Sisowath Quay, Phnom Penh’s lively riverside boulevard, in the back of a tuk-tuk, we pass designer restaurants on every corner, bars packed with bon viveurs and the beautiful people parading the latest selection of designer mobile phones. Blending in are cyclos that double as family saloons carrying up to six people, an elephant sauntering along the promenade on the hunt for bananas, and pigs and chickens dangling off motorbikes on their way to market.

Old Asia meets new Asia and it makes for a dizzying ride. The past has not been buried, it has been disinterred and dragged up for all to share, lest the world forget. But the new Cambodia is looking forward to a brighter future with open arms.

Need to know

Explore (08444 990901, www.explore.co.uk) offers a 15-day tour including the Tuol Sleng museum and Angkor Wat. Departures are on Dec 15 and throughout 2008, from £1,525pp.
Reading: First They Killed My Father(Mainstream, £12.99), Loung Ung’s memoirs of life in Cambodia. Cambodia (Insight Compact Guides, £5.99).

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