The underground city is promoted as an important tourist attraction by most Montreal travel guidebooks, and as an urban planning achievement it is impressive. For most Montrealers, however, it tends to be considered more as a large mall complex linking Metro stations—they may not even know they are in it. Many Canadian cities have some kind of tunnel or skywalk system downtown to help people avoid the weather. Most parts of the Montreal underground city are open while the Metro is in operation (5:30 AM to 1:00 AM), though some are closed outside of business hours. Maps of the underground city and the Metro can be obtained free of charge from all Metro stations, and the network of buildings is indicated on most maps of the downtown core. Nearly 500,000 people use it per day. It is also the largest underground complex in the world. It stretches for 32 kilometers (20 miles) and covers 4 million square meters (one and a half square miles). According to official statistics, its corridors link up with 10 metro stations, 2 bus terminals, 1,200 offices, about 2,000 stores including 2 major department stores, approximately 1,600 housing units, 200 restaurants, 40 banks, movie theatres providing 40 screens and other entertainment venues, 7 major hotels, 4 universities, Place des Arts, a cathedral, the Bell Centre (home of the Montreal Canadiens), and 3 exhibition halls: the Place Bonaventure, the Convention Centre (Palais des Congrès de Montréal) and the Olympic Centre. History of the central segment The vision for the underground city was originally that of urbanist Vincent Ponte, for whom a commemorative plaque was unveiled in November 2006 at Place Ville Marie. The first link of the underground city arose with the construction of the Place Ville Marie office tower and underground shopping mall, opened in 1962 and built to cover an unsightly pit of railway tracks north of the Central Station. Two tunnels linked it to Central Station and the Queen Elizabeth Hotel. The advent of the Montreal Metro in 1966, in time for Expo 67, brought tunnels joining Bonaventure station to the Château Champlain hotel, the Place du Canada office tower, Place Bonaventure, Central Station, and Windsor Station, forming the core of the Underground City. Square-Victoria-OACI station connected to the Tour de la Bourse, Montreal's stock exchange building. Adding to the development of the underground city was the Montreal Urban Community Transit Commission's policy of