The S21 prison is one of the saddest places I have ever been to in my entire life.

It has been left as it was found. A school turned into a warren of torture chambers. Iron bars and chains still hang on steel beds. The tiny single prisons that were made out of the classrooms are still there. Those on the first floor had brick walls and were about 2x2 meters. Each one enjoyed about a quarter of a barred window on the back wall. The cells on the second floor were wooden, half the size with no windows at all.

All of the cells had huge bolts on the floor to which was attached a big chain. Horrible.

1975 was 'Year Zero' according to Pol Pot and his regime. Time to wipe the slate clean and create a new population with the 'correct ideals'. The people on his target list were monks, the disabled, anybody in business, anybody educated, anybody speaking a foreign language, some say anybody wearing glasses - as this was thought to be a sign of having been educated, anybody from China, Laos or Vietnam. Anybody basically.

The school in Phnom Peng was taken over and used as a holding centre for prisoners before they were sent for execution at the killing fields.

Worse still was block B. Pol Pot's men decided that they would not only meticulously document and photograph every prisoner, but they would photograph the 'questioning' as well. The whole block is full of black and white photos - mainly mug shots of terrified, bewildered or furious men, women and children.

Others are of them being tortured. There are hundreds of them, all with expressions of either pleading sadness, sheer terror or bewilderment in their eyes. They all have the same haircut and a prison number. According to write-ups at the museum, none survived - not even the kids.

Visiting S21 was a numbing experience. Everyone walking around the place, male and female, was deathly silent and choking back tears. Everyone in our group automatically split up and walked around on their own. When we came out, nobody spoke for ages.

I went to Uni, I speak two foreign languages, I wear glasses to drive, my parents have their own business - they too speak foreign languages - so do my sisters and my brother.

I was really surprised to find the vibe at the Killing Fields to be really peaceful - the same as any other cemetery I guess. Only this one housed so many tortured souls.

I figured that at least here, despite how brutally they were murdered, they finally found peace.

Our guide was 14 when the Khmer Rouge took over. He was bitter and still had tears in his eyes when he pointed out the now empty graves at the Killing Fields site. Imagine how many times a day, every day he tells the same story and it still makes him cry.

What happened to these people was horrendous, unthinkable. And it was only 30 years ago. It happened to the Jews in WW2 and I guess then everyone said they would never allow such an atrocity to happen again. But similar things are happening in Somalia. It happened in Croatia. The weirdest thing about this is that they were doing it to their own people, same creed, same country.

Walking around you hardly ever see any old people in Cambodia. Most of them were murdered.

My boyfriend's mum mentioned to her Cambodian friends in France that we were here. They said they had no family left to put us in touch with because they had all been wiped out. It’s horrendous.

With those older people you do see, you can't help but wonder which side they were on. To be honest, I don't think it really mattered. Most of the adults in the Khmer Rouge knew full well that they had no choice to do what they were doing. That’s why those animal ‘leaders’ turned their children into monsters. Poison the minds that are not old enough to have an opinion or understand and then train them to kill without mercy. The guides will tell you stories of kids who grassed up their own parents. It just doesn't bare thinking about.