The 1967 World Expo left Montréal the Biosphere. This construction by Buckminster Fuller is an interesting object, and now surrounding the Museum of Water. Actually the design had transparant acrylic elements fitting in between the steel, but a fire in 1976 burned these away.
The Biospehere is in the Jean Drapeau Parc, on an island in the St. Lawrence River. It is an experiment in the way to get to a more sustainable society and the possibility to use buildings for this lifestyle. A next step was Biospehere 2 in the Arizona Desert near Tucson.
For more Montréal photos you may visit here.