As a teenager I read the Ann Frank diaries and learnt about the Second World War concentration camps, and later the American series Holocaust made a big impression on me. Over the years I have seen films and visited exhibitions and museums, including Yad Vashem in Jerusalem, that tell the story of the mass murder of Jews. But my visit to the former Nazi concentration and death camp Auschwitz-Birkenau was the first time I walked where some of the horror took place.
My visit, organised by the Holocaust Educational Trust, started at Leeds Bradford airport with over 200 16- and 17-year-olds who were more subdued than usual. The usual banter was also missing from the 9 Members of Parliament who accompanied them on the visit. We were all very aware that what lay ahead would be both upsetting and emotionally taxing.
At Krakow airport we split into groups of around 18 students, an educator who works with the Holocaust Education Trust and one or two MPs. Over the course of the day we learnt how Auschwitz developed, and the various changes the Nazis made as they mechanised the killing procedure and developed ways of making money out of the process.
The first visit was to the camp known as Auschwitz 1. Originally built as a prison camp there are large brick buildings, known as blocks, across the site. They look well built, and inside there are now a mixture of exhibitions and reconstructions of how people would have lived. I found myself thinking of slave ships trying to imagine between 700 and 1000 people in each one. The impact on people living so close together, without proper sanitary facilities and while being slowly starved is hard to imagine.
One hut has photographs of victims on the wall - with date of birth, date of arrival and date of death - just days or weeks after they arrived. I found myself looking for women born in the late 1920s, a similar time to my Mum, and imagining what their lives could have been like if they had not been murdered.
I found it was an individual's possessions that were most moving. In a pile of shoes, each pair was different, chosen by someone, worn by someone and still showing the evidence of the shape of their foot. The pile of suitcases with names and dates of birth was equally poignant, the children's clothes and broken toys heart-breaking beyond words.
The horror is perhaps most acute when standing in one of the early gas chambers and wondering how many people died on the very spot where I stood. The tons of human hair that were found when the camp was liberated were piled up in one room. Hair shaved from the victims was sold to make cloth and act as padding.
Trying to comprehend the numbers of people is a challenge when they are so huge, remembering that these were all individuals is important. The Holocaust Education Trust tries to help this by emphasising individual stories through survivor testimonies and pictures of victims' lives before the war.
We then drove to nearby Birkenau - the Nazis' extermination camp. The size of the camp is shocking. The railway line into the middle of the camp, familiar from many films, bisects a vast flat area of 400 acres which disappears into the horizon. Many of the original wooden huts have disintegrated and just the brick chimneys remain, but there are some reconstructed huts which are used to illustrate living conditions.
During 1944 most people arriving at Birkenau were taken straight to the gas chambers, with only those fit enough to work spared. To reduce any panic those about to die were told they were going to have a shower, they undressed and entered what they thought was the shower room - instead it was the gas chamber. Special squads of prisoners removed the bodies and transported them for burning - in time they too were killed. The gas chambers and crematoria were partially destroyed by retreating Germans toward the end of the war.
The young people in my group, from schools in Sheffield and Rotherham, had different reactions to what they saw and heard. Some found it hard to take in just what had happened, others felt they would look at racism in a different way, seeing where it could lead. At the end of the day we stood for short time of reflection, some of the young people reading poems. A rabbi read a psalm and sang a prayer.
The killings at Auschwitz of Jews, gypsies, disabled people, enemies of the regime is far from the only time that mass murder and genocide has happened. It's the scale, the organisation, the industrialisation of the process and the determination to make money that is difficult to believe. And that so many people, while not themselves directly killing, colluded in the process. Such wickedness is almost incomprehensible.
As I look back at the photographs I took, it feels more shocking, more horrific. The Holocaust Education Trust knows that visitors all react differently and their feelings and emotions change. They will be meeting the young people again shortly to reflect on the visit and to help them draw their own lessons from an extraordinary day.
For details of the Holocaust Education Trust, visit their website