About 200 teenagers from East Anglia have travelled to Poland to visit Auschwitz as part of a £1.5m government initiative.
A visit brings greater understanding of the Holocaust, the trust says
They are the first in Britain to take part in the course which offers experience of the Holocaust.
The Holocaust Educational Trust says visiting the camp provides a greater understanding than lessons alone.
Pupils were shown barracks, inmates' registration documents, clothes and other personal items seized by guards.
Rachael Saffer, from Queenswood School in Hatfield, Hertfordshire, said: "It has been difficult. As much as I want to look I really find it hard to.
"It does strike a lot of buried emotions I didn't think I would grasp by coming here," she said.
Kay Andrews, from the trust, accompanied the students from schools in Cambridgeshire, Suffolk, Norfolk, Bedfordshire and Hertfordshire.
HISTORY OF AUSCHWITZ
Construction began in 1940 on site which grew to 40 sq km (15 sq mile)
At least 1.1 million deaths, one million of them Jewish
Other victims included Poles, Roma (Gypsies), Soviet POWs, homosexuals, disabled people and dissidents
Of 7,000 Nazi guards, 750 were prosecuted and punished after the war
Pupils visited the gas chambers and crematoria at Birkenau - a second camp close to where Auschwitz prisoners were taken to be gassed.
"We hope to encourage students to question the world that they live in a way that challenges what they see around them. Rather than taking it for granted and accepting it," Ms Andrews said.
More than a million people - mainly Jews - were killed at Auschwitz during World War II.