The Carrière Wellington is a museum built inside the actual WWI chalk tunnels south of the city centre. Unlike Les Boves (the tourist tunnel under the Grand'Place), Wellington is a purpose-designed underground museum with proper interpretation, replica barracks, life-size figures, and original soldier graffiti. Tours last about 75 minutes and are led by guides in English and French. The entrance is on Rue Arthur Deletoille.
The museum gives a visceral sense of what it was like to live underground before a major offensive. The tunnels held around 24,000 soldiers — British, New Zealand, South African, and Australian troops — in conditions that were cramped but not unbearable: the chalk kept the temperature constant, water dripped from the ceiling, and the men scratched their names and cap badges into the walls. The exit of the tour brings you back to daylight at a different point, giving a moment of genuine relief that the soldiers who emerged here would have felt before walking into the battle.