Thrusting upwards from the west and facing the St. Lawrence River, Cap Diamant reaches a height of 100 meters and commands an extensive and varied panorama. Sitting atop this is Québec's star-shaped Citadel, a massive fortress protected by thick walls, ramparts, and ditches that was built in 1832. 

Still an active military post, the Citadel is used as military quarters for generals, officers, and servicemen, as well as the summer residence of the Governor General of Canada. It is also the headquarters of the 22nd Canadian Regiment, which formed at the beginning of the First World War and boasts a distinguished record, including action at the Battle of the Somme and, much later, in the Korean War. 

Summer visitors can watch the Changing of the Guard ceremony each morning, and the military museum, located in the mid-18th-century powder magazine in the southern corner of the Citadel, is open year-round.