The drive from the airport was beautiful. Tree-lined country roads took us through quaint villages and gentle countryside — an idyllic scene in the spring sunshine.

There was nothing to hint that nestled away in the picturesque northern German landscape was the site of Bergen-Belsen, one of the most infamous concentration camps. A place where thousands of people died.

I travelled as part of a Holocaust Educational Trust delegation of over 200 British students and teachers visiting the camp on Sunday to mark the 70th anniversary of its liberation.

On April 15, 1945, the 11th Armoured Division of the British Army entered the Bergen-Belsen camp. They were greeted by survivors who were little more than skeletons. Around 70,000 inmates had died from disease and starvation. One of the victims was Anne Frank.

The British troops destroyed the camp’s buildings to prevent the spread of disease. So now, entering through a concrete tunnel, you emerge into what is a large field dotted with raised mounds. Signs at each mound show how many thousand people were buried in the mass graves beneath.

The HET group joined a party from the Association of Jewish Ex-Servicemen and Women for a ceremony at the Jewish memorial. The Shabbaton Choir sang the Shema and Chief Rabbi Ephraim Mirvis gave an address. “No words can sum up our deep sense of grief and anguish and sorrow, and no words can adequately do justice to their memory,” he told the two groups, as the rain pelted down.

Walking round the site, former British soldier Bernard Levy recalled the scene he encountered as one of the liberators. “They weren’t really people here, they were semi-corpses,” he said.

Ajex member Mervyn Kersh was stationed in the nearby town of Celle during the liberation. He said: “I saw the people who could still walk making their way in their camp uniforms to the station in Hanover. It was a long way but they did it. Obviously they were the stronger ones.

“I spoke to dozens of them in a mix of English, French, German and sign language. They mostly talked about what they wanted to do once the war was over. All except one wanted to go to Eretz Israel. I didn’t find one who wanted to go back to their country — even to look for their family.”

The HET group moved on to the camp museum. Sixth-former Hannah Averill struggled to reconcile the pleasant countryside with the presence of the mass graves. “This is really harrowing. I’ve been to Auschwitz but this feels more personal. You see where thousands of people are buried.”

Ms Averill hopes to become an HET Young Ambassador: “I think every human being needs to understand the extent of the horror we can do to another person.”

The HET visit was part of the international commemoration attended by German president Joachim Gauck and World Jewish Congress leader Ronald Lauder. Herr Gauck paid tribute to the camp inmates. “We must look to the past to put an end to injustice,” he said. “We commit ourselves to the obligation of never denying these crimes, or relativising them, and of preserving the memories of the victims.” He thanked Great Britain for liberating Bergen-Belsen.

Around 90 Belsen survivors attended the ceremony.

Next stop for the HET group was the Bergen-Hohne Garrison, which was transformed into a displaced persons’ camp for survivors. The neatly lined buildings were home to the SS during the war. In the officers mess there is a gallery where Heinrich Himmler used to sit. A bronze Nazi eagle insignia remains visible, although its swastika was long ago removed.

As the sun came out, the group joined a moving ceremony at the Jewish cemetery, led by members of Ajex and British soldiers. Menachem Rosensaft, who was born in the DP camp, told the gathering that 13,000 people who emerged from Bergen-Belsen died there from disease and the ravages of starvation in the two months after the liberation.

Mala Tribich was one of those who managed to survive. She said: “When survivors are no longer here, it is the future generation we rely on to keep the memory going. It is never too early for them to start.

“There are families that have been so completely wiped out that there is nobody to remember them and if we don’t it will be as if they had never existed. The memory will just be annihilated, which is what Hitler wanted.”

HET chief executive Karen Pollock said that the 70th anniversary could be regarded as a turning point in the way the Holocaust was remembered.

“We know that, sadly, many eye-witnesses may not be around for the next significant anniversary. We are acutely aware that the Holocaust is moving from living history to just history,” she said.

The day ended with participants invited to leave their own messages at the cemetery. The sight of the teenagers placing on the memorial white stones on which they had written “never forgotten” and “remember” suggested the memory of victims may be in safe hands.