Each year, staff take S3 (Year 9) on a five-day tour of sites in Belgium and France, including Tyne Cot Cemetery, the Sanctuary Wood trench network and the Menin Gate.
It began five years ago as a history department trip, but it had such an impact on pupils that it was expanded to include the entire S3. Last year, more than 130 pupils made the trip.
"The trip's no longer just about history," says Gavin Clark, deputy headteacher. "It's the centrepiece of the school's approach to citizenship and inclusion. It provides a real opportunity for pupils to reflect on their own lives and their role in the community."
Participants immerse themselves in the past by becoming the "Dunbar Pals Battalion". In the First World War, Pals Battalions were recruited from factories and community clubs. All sorts of people joined up together - and were killed together. It's a sobering thing for the youngsters to consider.
The pupils are in character from the moment they set off from school on the buses with bagpipes playing. They have no access to mobile phones and no internet and learn First World War songs on the bus, which they belt out.
This interactive approach is the brainchild of Des Brogan, a former history teacher who now runs Mercat Tours International, theEdinburgh-based company that organises the trips.
"We try to immerse the kids completely in the past," he says. "By the time they get back home they shouldn't know whether they're in 2007 or 1914."
Early in the trip, pupils stand in the Sanctuary Wood trenches near Ypres, facing the German lines. They close their eyes and imagine they're waiting for the order to go over the top. Instead of merely following in the soldiers' footsteps, they enter into their minds.
Later, they visit the cemetery at Essex Farm where John McCrae wrote the poem In Flanders Fields and see the grave of a boy aged 15, who went into the army with his friends.
The climax of the tour is a visit to Ypres. Pupils take part in the nightly ceremony for the sounding of the Last Post, and later lay their wreaths and tributes at the Menin Gate.
"The pupils get more out of visiting the sites as the Dunbar Pals Battalion than they could get in the classroom", says Gavin. "They come back as more mature and reflective individuals. Many parents tell me it was an important experience in their children's lives."
Lesley Gillies, the school's principal teacher of inclusion, agrees. "At first, kids think of the trip as just a holiday. But each new experience helps them discover things about themselves emotionally. Young people tend to think the world revolves around them. But you see them develop empathy through their understanding of what happened to an earlier generation."
Marian Black visited the grave of her grandfather's cousin on last year's trip. "That was moving for me," she says. "My friends were crying too - even though they didn't know anything about him." The effect is lasting. Jordan Kerr, a pupil who went on the trip three years ago, thinks it made a profound impression on her. "We saw the field where both sides played the famous Christmas football game. Later, there were reports that the Germans cried when they were ordered to shoot the enemy down as they advanced. They weren't killing machines - they were just young men."