The free, 3½-hour tours of this massive hydroelectric facility start with an introduction to hydroelectricity. Then you'll be taken inside and outside the massive LG2. Together with LG2A, it's the world's largest underground power station – as tall as a 15-story building but buried 140m deep in the bedrock. It produces 25% of the province's energy and ranks among the top handful in size globally. For English-language tours, reserve at least 48 hours in advance.
Advance reservations are required for French-language tours as well (1pm Tuesday, Thursday, Saturday and Sunday from mid-June to August, 1pm Monday and 8:30am Wednesday and Friday September to mid-June).