The Calgary Tower is a 191-metre (626 feet) free standing observation tower in Downtown Calgary, Alberta, Canada. Originally called the Husky Tower, it was conceived as a joint venture between Marathon Realty Company Limited and Husky Oil as part of an urban renewal plan and to celebrate Canada's centennial of 1967. The tower was built at a cost of $3,500,000 and weighs approximately 10,900 tonnes, of which 60% is below ground. It opened to the public on June 30, 1968 as the tallest structure in Calgary, and the tallest in Canada outside of Toronto.