The duke of Wellington had this partially star-shaped fortress built at the south end of the city walls in anticipation of renewed American attacks after the War of 1812. Some remnants of earlier French military structures were incorporated into the Citadelle, including a 1750 magazine. Dug into the Plains of Abraham high above Cap Diamant (Cape Diamond), the rock bluff adjacent to the St. Lawrence River, the fort has a low profile that keeps it all but invisible until walkers are actually upon it. The facility has never actually exchanged fire with an invader, but still continues its vigil for the state. It’s now a national historic site and, since 1920, has been home to Québec’s Royal 22e Régiment, the only fully Francophone unit in Canada’s armed forces. That makes it North America’s largest fortified group of buildings still occupied by troops. Admission includes a guided tour to the Citadelle and its 25 buildings, as well as entrance to Le Musée Royal 22e Régiment, which celebrated its 100th anniversary in 2014 with a major expansion and a new permanent exhibit, “Je me souviens.” The long walk could test the patience of younger visitors and the legs of many older people, though. For them, it might be better simply to attend the 35-minute choreographed ceremony of the Changing of the Guard, which runs from daily at 10am from June 24 until the first Monday of September. It’s an elaborate ritual inspired by the Changing of the Royal Guard in London and is included in the regular admission fee. Note that it can be cancelled if the weather’s bad.