4 Best Sights in Quebec City, Quebec

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 is, quite literally, the star of the Fortifications of Québec National Historic Site. It 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.

Since 1920, the Citadelle has served as a base for Canada's most storied French-speaking military formation, the Royal 22e Régiment, 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 du Royal 22e Régiment in the former powder magazine, built in 1750. 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. You must take a tour to access the Citadelle, since it's a military base.

The location—set high above the St. Lawrence river with stunning views of the city and surrounding countryside—is worth a visit even if you don't want to pay (or wait) to take a tour.

Thick stone walls stretching for 5 kilometers (3 miles), connected by four gates, and adjoined by forts, bastions, and even a citadel: with such a special and unique landmark, it's not difficult to understand why the Historic District of Old Québec is a UNESCO World Heritage Site. These nearly intact ramparts, virtually the only ones of their kind in North America, recall the complex history of the French and British regimes in Québec City. French colonists began building ramparts along the city's cliffs as early as 1690 to protect themselves from the British, but they had trouble convincing the French government to take the threat of invasion seriously. And when the British did invade in 1759, the walls were unsurprisingly still incomplete. The British, despite attacks by the Americans during the American Revolution and the War of 1812, took over a century to finish them—and they never saw armed conflict.

From June to September, two guided tours are offered: one starts at Artillery Park and focuses on the social and architectural heritage of the ramparts, while the other is more military-focused and begins at Terrasse Dufferin. Either way, the Dauphine Redoubt in Artillery Park on the northern end of the fortifications should not be missed; it's one of the oldest military buildings in the Americas. The four gates—Saint-Jean, Saint-Louis, Kent and the more modern Prescott—are well worth a stop, too.

The strategic importance of Artillery Park, part of the Fortifications of Quebec, lies in its prime location overlooking both the plateau to the west of the city, from which an army could lay siege to it, and St. Charles River, where boats could land soldiers. Under French rule, all the lines of defense that were proposed or built passed through this territory. By the end of the 17th century, the park was already recognized as a strategic site and both French and English military engineers erected various fortifications here over the years. The lavish Quartier des Officiers, built in 1712, was used as officers' quarters of the Royal Artillery until the late 19th century, when the Canadian government converted the barracks into a cartridge factory following the departure of the troops. It would go on to play a predominant effort in both of Canada's world-war efforts; several thousand men and women of Quebec worked there.

Of the 16 Martello towers in Canada, four were built in Québec City because the British government feared an invasion after the American Revolution. In summer, visitors can tour Martello Tower No. 1, and watch a presentation on the history of the four structures. A haunted maze is held for youngsters on Halloween at Martello Tower No. 2, at avenues Taché and Laurier, and a mystery dinner show is available by reservation. Martello Tower No. 4, on rue Lavigueur overlooking the St. Charles River, houses an escape room game, The Tormentor, in the summer months.