This massive, star-shaped fort towers above the St Lawrence River on Cap Diamant. French forces started construction here in the late 1750s leaving a gunpowder building and a redoubt, the beginnings of a defensive structure. But the Citadelle we know today was actually built by the British, who feared two things: an American invasion of the colony and a possible revolt by the local French-speaking population (that’s why the cannons point not only at the river, but at Québec City itself). However, by the time the Citadelle was completed (construction began in 1820 and was finished about 30 years later) things were calming down. Twenty years later, in 1871, the Treaty of Washington was signed between the United States and the newly minted Dominion of Canada (on behalf of Her Majesty the Queen of England, of course), ending the threat of American invasion. The Citadelle now houses about 200 members of the Royal 22e Régiment (the rest live with their families at the nearby Valcartier base). The Vandoos, a nickname taken from the French for 22 ( vingt-deux ), is the only entirely French-speaking battalion in the Canadian Forces. It has a reputation among the Forces as the toughest (ie badass) regiment in the army. The hour-long guided tours are excellent and will give you the lowdown on the spectacular architecture and get you into exhibits on military life from colonial times to today. The changing of the guard ceremony takes place at 10am each day in the summer months. The beating of the retreat, which features soldiers banging on their drums at shift’s end, happens every Friday at 7pm from July 6 until early September. The second official residence of the governor general (the Queen of England’s representative in Canada) has been located here since 1872 (the other residence is in Ottawa and called Rideau Hall). There are free one-hour tours of the Citadelle residence.