It turns out that most of the Expo67 Pavillion buildings were dismantled in 1981. According to this account, this was due to the fact that “the buildings had fallen into disrepair”. Now these islands are “mainly used as parkland and for recreational use, with only a few remaining structures from Expo 67 to show that the fair was held there.” There is a blogger out there who has set-up an online museum of Expo67 and you can view some recent photos of the ruins here. Your comments here have piqued my own interests, and now I am considering a documentary excursion to the site – perhaps during the 2009 Montreal Jazz Festival.

I thought that most of the original buildings remained, but apparently:

After 1967, the site struggled for years as a standing collection of international pavilions known as “Man and His World.” However, as attendance declined, the physical condition of the site deteriorated, and less and less of it was open to the public. In 1975 the Île Notre-Dame section of the site was completely rebuilt around the new rowing basin for Montreal’s 1976 Summer Olympics. Space for the basin, the boathouses, the changing rooms and other buildings was obtained by demolishing many of the former pavilions and cutting in half the area taken by the artificial lake and the canals. In 1976, a fire destroyed the acrylic outer skin of Buckminster Fuller’s dome. With the site falling into disrepair it began to resemble ruins of a futuristic city. In the late 1970s, scenes for Robert Altman’s post-apocalyptic ice age film Quintet were shot on site, as was the “Greetings from Earth” episode of Battlestar Galactica, which portrayed it as the ruins of a city left behind after a biological attack. The music video for the song Ghost Town by Cheap Trick was also shot on this site. Some of the footage showing the United Kingdom pavilion was reused in Buck Rogers. Minor thematic exhibitions were held at the Atlantic pavilion and Quebec pavilion, until the Montreal Casino was built. The remaining original exhibits of the site closed for good in 1982.

After the Man and his World exhibition was discontinued, the former site for Expo 67 on Île Sainte-Hélène and Île Notre-Dame, has been incorporated into a municipal park run by the city of Montreal. In the year 2000, the park was renamed from Parc des Îles to Parc Jean-Drapeau, after the mayor that brought the fair to Montreal. In 2006, the corporation that runs the park also changed its name from the Société du parc des Îles to the Société du parc Jean-Drapeau. Two prominent buildings remaining in use on the Expo grounds are the Buckminster Fuller dome (now operating as an environmental sciences museum called Biosphère) and the Habitat 67 residences. Also, the French and Quebec pavilions now form the Montreal Casino. La Toundra Hall is part of the surviving structural remains of the Canadian pavilion. It is now a restaurant and special events hall. Another part of the pavilion now serves as the administration building of Parc Jean-Drapeau. Katimavik’s distinctive inverted pyramid and much of the rest of the Canadian pavilion were dismantled during the 1970s. The Jamaican pavilion is still standing, and Place des Nations, where the opening and closing ceremonies were held, also survives. A part of the Korean pavilion remains as a shelter for the bus route that connects with the metro station. Additionally, the former Tunisian Pavilion exists as a City of Montreal/Parc Jean Drapeau administration and logistics center. It is within the vicinity of the Cosmos Bridge, which connects Ile-St-Helene to Ile-Notre-Dame. The bridge linked the two islands and at either end were the American and Soviet Pavilions respectively. Other remaining structures include sculptures, lampposts and landscaping. The rapid transit subway system still has at least one “Man and His World” logo on a station’s wall. La Ronde survives and is expanding. In 2001 it was sold to the New York amusement park company Six Flags. The Alcan Aquarium built for the Expo remained in operation for a couple of decades until its closure in 1991.

The Labyrinthe is indeed still standing. As I said in the post above:

In May 2007, the NFB and the Cinémathèque Québécoise presented an exhibition at the Labyrinth pavilion, marking the 40th anniversary of Expo 67.

thanks for turning me on to this.