Built at the city's highest point, on Cap Diamant, the Citadelle is the largest fortified base in North America still occupied by troops. The 25-building fortress was intended to protect the port, prevent the enemy from taking up a position on the Plains of Abraham, and provide a refuge in case of an attack. Having inherited incomplete fortifications, the British completed the Citadelle as protection against French and, eventually, American attacks. However, by the time it was finished in 1832, the attacks against Québec City had ended.
Since 1920 the Citadelle has served as a base for Canada's most storied French-speaking military formation, the Royal 22e Régiment (Royal 22nd Regiment), known across Canada as the Van Doos, from the French "vingt-deux" (22). Firearms, uniforms, and decorations from as far back as the 17th century are displayed in the Musée Royal 22e Régiment (Royal 22nd Regiment Museum) in the former powder magazine, built in 1750. If weather permits, you
can watch the Changing of the Guard, a ceremony in which troops parade before the Citadelle in red coats and black fur hats while a band plays. The regiment's mascot, a well-behaved goat, watches along. The queen's representative in Canada, the governor-general, has a residence in the Citadelle, and it's open for tours in summer. Québec City's oldest military building, the Cape Diamond Redoubt, was constructed in 1693 under the supervision of the engineer Josué Boisberthelot de Beaucours and is now included in the guided tours. A guide must accompany visitors to the Citadelle since it's a military base.