This morning, we come face to face with the horrific crimes of the Khmer Rouge. Tuol Sleng was a former high school that the Khmer Rouge turned into a centre for interrogation, torture and death. Today it is a museum of torture and serves to remind visitors of the terrible atrocities that came to pass in Cambodia. 17,000 people passed through the gates of this prison and only seven lived to tell the tale. The Khmer Rouge were meticulous in their record keeping, photographing all the prisoners and many of these haunting black and white images are on display in the cells. Enemies of the revolution were killed here, as well as many Khmer Rouge loyalists, denounced by an ever more paranoid political party. It became a production line for killing, as those that worked within its walls were unwaveringly loyal to Pol Pot. The party did not make mistakes, so those sent here had to be guilty. The role of the prison was not to prove innocence but to confirm guilt. Tuol Sleng is a profoundly moving experience and not everyone will want to visit. However, it is key to understanding the hell into which Cambodia descended and how far it has come in the years since.

We travel out of town to the Killing Fields of Choeng Ek. Prisoners from Tuol Sleng followed this same route to their fate. An old Chinese cemetery, Choeng Ek was turned into an extermination camp for political prisoners. The remains of 8985 people were exhumed from mass graves and are kept in a memorial stupa here. Despite the horrors of the past, it is a peaceful place to go and a tranquil spot to reflect on the tragic events that engulfed Cambodia and its people.

We explore the stunning Royal Palace complex, home to the Cambodian royal family and a symbol of the nation. We begin amid the beautiful royal gardens, landscaped with tropical plants and studded with gleaming spires. We enter the Throne Hall where the royal receptions are held and the Cambodian king's coronation took place. We then pass the Napoleon III Pavilion made from iron, a gift from the French emperor in the 19thcentury.We continue to the Silver Pagoda, named after the 5000 silver tiles covering the floor, each weighing 1kg. Inside are some of the country's most cherished treasures, including a life-size gold Buddha studded with 9584 diamonds, the largest weighing 25 carats.

We leave Phnom Penh on National Highway 5 and travel to the former Cambodian capital of Udong. The capital from 1618 to 1866, we explore the sacred hills here, which include historic pagodas and several stupas containing the remains of Cambodia's former kings. There are panoramic views over the Cambodian countryside in every direction. After an extensive visit to this historic place, we return to the Cambodian capital.

With its distinctive art-deco dome, Phnom Penh Central Market (Phsar Thmey) attracts visitors with hundreds of traditional Khmer stalls, selling everything from antique coins and brightly colored fabrics to traditional crafts and medicinal products. No first-time visit to Phnom Penh is complete without stopping, and shopping, here.

In the late afternoon, we board a local boat for a sunset cruise on the river. We set off on the Tonle Sap River, which famously reverses direction each year, acting as the world's largest natural flood barrier for the Mekong River. We cruise past the Royal Palace compound and around the Chrouy Changvar Peninsular on to the mighty Mekong River. We cruise past small villages and see fishing boats preparing their catch. We return to Phnom Penh after dark.

We make for Wat Phnom, a symbol of the city. Located on one of the few hills in this pancake-flat capital, the first pagoda was originally built in 1373 to house Buddha statues discovered in the Mekong by a woman named Penh. This gives us the modern name of the city, Phnom Penh or Hill of Penh. Cambodians come to the shrine to pray for luck in love and life, employment and exams, so there it is always a bustling place.

This monument was built after Cambodia had got full independent from Franch Colonization in 1953.

We travel to the Russian Market, one of the premier shopping destinations in the Cambodian capital. Known as Psar Tuol Tom Pong, it earned its nickname in the 1980s, when Russians were the only tourists in Cambodia. A rambling place, it is bursting with bargains, including handicrafts, carvings, silk and textiles, clothing and footwear, and lots of pirated software, CDs and DVDs, not forgetting enough motorcycle parts to assemble a homemade moped.