This island in the St Lawrence River still bears interesting traces of its use as a World War II prison camp, a fort and a 1967 World's Fair. Today you can take public transport, a car, bike or walk from the mainland to the island's many attractions, which include an amusement park at the north of the island, an old fort in the middle, and World Fair gardens and a biosphere to the southeast.
Giant amusement park La Ronde, owned by US-based Six Flags, has bone-shaking thrill rides, including Le Splash, which will leave you soaked, Le Monstre, the world's highest wooden roller coaster and Le Vampire, a suspended coaster with five gut-wrenching loops. There's also a good assortment of kiddie rides, live shows and a minirail with good river and city views. In July to early August, the park hosts fireworks as part of L'International des Feux Loto-Québec on Wednesday and Saturday nights.
Near La Ronde stands an old fort built in the 19th century by the British to defend Montréal from an attack by the Americans. Inside the stone ramparts is the Musée Stewart, where a collection of old maps, documents, navigational equipment, firearms and other artifacts traces the early days of Canada. Seasonal activities include a 'game' of recreating island-escape attempts by World War II prisoners! A glass tower offers views across the Montréal mainland.
Walkways meander around the island, past gardens and among the old pavilions from the World's Fair. One of them, the American pavilion in the spherical Bucky Fuller dome, has become the Biosphère. Using hands-on displays, this center explains the Great Lakes-St Lawrence River ecosystem, which makes up 20% of the planet's fresh water reserves; demonstrates sustainable living and low energy consumption; and provides tours of a self-sufficient, solar-powered home. There's a great view of the river from the Visions Hall.