It rained torrentially all night, the lightning hardly stopped and every now and then the thunder shook the room. Oh, and I forgot to mention that we heard Hotel California last night on an advert for The Eagles' Asia tour.

After breakfast of a cheese sandwich, our tuk-tuk driver set off. Most of Phnom Penh's roads are paved but it wasn't long before we met the dirt tracks with large holes and brown puddles, and the tuk-tuk had no suspension, so we felt every bump. But it didn't take long until we reached the Tuol Sleng museum, a high school that was turned into a prison camp by Pol Pot's soldiers in the 1970s. Over fifteen thousand people were held there over four years, and only seven made it out alive, the rest were beaten and tortured to death, or taken out to mass grave sites in the countryside and executed.

We were inundated by people begging as we stepped off the tuk-tuk: lots of children greeted us with outstretched hands, and men with no arms or legs, or blind men asked for money. We decided not to give money away because it was too hard to give to one and not to others, but we've made donations to charities around in the hope that it would help people more fairly. It's very hard to say no to them, though. Once we'd paid the entrance fee we wandered round the site. The school buildings were almost all left as they were found. Fourteen bodies were discovered at the prison when Pol Pot's regime ended, and these were burried in the grounds. The first prison block had a photograph of each body, as it was found, with the original bed and leg irons in the same place. Then there was a list of rules that the prisoners had to obey, which included not talking or moving at all or they would be beaten or subjected to electric shocks. The second school building was surrounded with barbed wire (to stop those on the top floor from trying to throw themselves off the top floor) and all the rooms were filled with black and white photos of the prisoners kept here, tiny passport-sized pictures on board after board. There were a lot of women and children on some boards, and many more of men. These rooms had originally been split into tiny cells, about a foot wide by six feet long, and the prisoners attached to metal bars. The walls had been taken down for the photo displays, but the floors still showed the outlines of the cells.

The third building had the cells still intact, tiny dark rooms with hardly any light or ventilation. The walls were built of brick here, but wood on the second and third floors. The fourth block had a section showing the torture methods used to extract information, with big paintings done by a former inmate. Some of the tools used were on display. Upstairs were the large prison rooms where hundreds of people lay side by side on the floor, chained to a central bar. We watched a documentary about the prison, following the story of a girl and her husband, which had interviews with their families and some of the people working at the prison, as well as letters that they wrote to one another. It finished with a former guard showing how he made prisoners kneel at the edge of mass graves and hit them at the back of the neck with an iron bar before their throats were cut. He said he only hit them, he didn't kill anyone. The film was quite horrible, and, with awful timing, a baby started crying outside as the film was closing and the narrator was describing how babies were just dropped into the graves. We left very subdued again.

There was a display on the top floor of photos of Khmere Rouge soldiers and interviews with them on how they felt about their actions. Almost all of them said that they had to do what they were told or they would be killed, and almost all said that they would welcome a trial so that people could find out what went on.

Out tuk-tuk driver took us out to the killing fields then, where thousands of people were executed and burried in mass graves. This is only one of hundreds of sites in the country. We travelled about ten miles of unpaved roads, giant holes and masses of mud. It was a singularly uncomfortable drive, but we got there in the end. More people accosted us for money and children waved and said hello and then held out their hands.

The first thing we saw was a giant white stupa, a memorial building made of glass and marble. As we approached I could see what it contained: shelf upon shelf of human skulls. A small part of this area has been excavated recently in an attempt to find out just how many people were massacred by Pol Pot - estimates range from two to five million Cambodians killed.

Behind the memorial were the fields themselves, muddy after last night's rain. Grassy pits full of water showed where excavations had taken place, and we heard a guide explaining that only skulls were removed from the graves, as it was too time-consuming to take out all the bones. In the rainy season, like now, more bones came to the surface. As he spoke, we noticed that we were walking on a path that had human teeth in the mud, and further along we could see scraps of material and long white bone fragments under our feet. It was the most horrible feeling, that there was no way of not walking on human remains.

A part of these fields have not yet been dug up, and to one side were farmers with rice paddies, while in one of the largest trenches, dogs and cows drank. I didn't want to think about how many dead people were in there. Graves were marked along the way, with signs that said a hundred bodies were found here, or that the hundred people burried here had no skulls - the heads had been taken to prove that prisoners had been killed. There were graves only for women and babies, and graves for children. It just went on and on. Because the ground was so wet and the pits were full of water, the air was a mass of dragonflies that would have been beautiful on any other day. We left the killing fields of Cheung Ek feeling slightly numb at the thought that people can do this to one another.

Then we went back along the rutted roads, past the rice fields and the raised paths to villages that have become causeways in the wet. We ended up in a market, a massive covered affair full of people desparate to sell us something. We really didn't need any of the shoes, bags or silk trousers on offer, so we changed some US dollars for Cambodian riel (at a very good exchange rate) and then went to find something to eat. We had no luck with street stalls as there seemed to be very little on offer, so we asked the tuk-tuk driver to recommend a cafe and he pointed up the road. We found a strange little place hidden away that had all sorts of goodies on the menu, including a ploughman's lunch, which I couldn't resist. Then we went up to the Royal Palace and Silver Pagoda which were beautiful, if slightly tatty, buildings with intricate roofs and decoration. I was a bit upset that a man demanded that I put my camera away at a 'No Photography' sign, as I had no intention of taking pictures, but I suppose Westerners by and large deserve the reputation they have. At the next temple, where photography was permitted, a couple of women stepped over a few people praying so that they could stand in front of the Buddha statues and have their pictures taken. I was horrifed but they were gone before I could say anything.

It was quite late by this time, but our tour wasn't finished yet. The good thing about having our own driver was that all the other tuk-tuk drivers left us alone once they saw him. He took us to the National Museum which was a very interesting collection of statues and stonework, but didn't really teach us a lot about the country. We were continually urged to place flowers in front of Buddhist statues for good luck, and the sweet-smelling sticks of flowers were pressed into our hands despite our protests. We kept looking back at the person offering them in the hope that they'd show us what to do, but they all made encouraging hand movements and left us to it. We tried to be as respectful as possible but we both felt slightly awkward taking part in something we didn't really know anything about.

Our last stop of the day was the Elephant Pagoda, a small temple on a large hill. Every step had a blind or limbless beggar on it. We climbed to the top, had a bit of a look, and then went back to the tuk-tuk, tired and hot. Along the way back to the hotel we passed some incredible housing - filthy concrete boxes on top of one another all in a field with a market underneath. They all had laundry on their balconies and tiny, tiny rooms, some of them completely open to the front, and some mended with sheets of metal or wood. It showed just how poor the people of Cambodia are.

Just before our hotel, the tuk-tuk died. Its chain came off so Mikey and the driver pushed it the 50 yards or so to the hotel along the muddy road. We went out to phone Robin for his birthday and found an internet cafe that did cheap international calls via the internet. It was a very bad connection, though, with an eight-second delay, so unfortunately the call didn't last long. Nice to talk to my brother though.

We had supper at the hotel and then read for a bit in our nice cool room!