Biosphère

The Biosphère is Buckminster Fuller's geodesic dome — a 62-metre-diameter steel lattice sphere built as the United States Pavilion for Expo 67 that has become one of the most recognisable structures in Montreal and one of the most important buildings of the 20th century. The dome was originally covered in acrylic panels that created a transparent skin, but a fire during renovations in 1976 burned away the panels, leaving the bare steel skeleton that stands today — a building that is arguably more beautiful without its skin than with it.

Fuller designed the dome as a demonstration of his geodesic principles — a structure where the triangulated frame distributes loads so efficiently that the building weighs a fraction of what a conventional structure of the same size would require. The dome housed the US exhibition during Expo 67, which drew 50 million visitors and established Montreal as a world city. After the fire, the dome stood empty until 1995, when it was converted into an environmental museum focused on water ecosystems and climate change.

The museum inside is fine — interactive exhibits on Great Lakes ecology, water management, and climate science — but the building is the real attraction. The steel lattice, silhouetted against the sky on Île Sainte-Hélène in the middle of the St. Lawrence River, is one of those structures that looks equally impressive from across the water and from directly beneath, where the geometry of the triangulated frame creates kaleidoscopic patterns against the clouds. The surrounding park — part of Parc Jean-Drapeau, the former Expo 67 site — includes the Circuit Gilles-Villeneuve (Montreal's Formula 1 track) and Alexander Calder's monumental sculpture 'Man.'