One of Calgary's landmark buildings. The business centre is in the towers complex is connected by the Plus 15 skywalk - a climate-controlled, covered walkway 15ft above ground that links offices around the city. There is a health club in the, the Calgary Transit station is a block from the building and the airport is only a 20-minute drive away. Best location for lawyers due to close proximity of the courthouse. Oil and gas remain the largest industries in Calgary, which is home to large Canadian and global companies including BP, Shell Canada, EnCana, TransCanada and Suncor Energy. Agriculture, hi-tech and service industries are also key to the city's economy. Imperial Oil and Canadian Pacific Railway have located their headquarters here and are among Calgary's largest employers, along with telecommunications giants Shaw Communications and TELUS, Nova Chemicals and oil companies Nexen and CNRL. Calgary is also a destination for winter sports and tourism