The CN Tower is a 553.3 m-high (1 815 ft) concrete communications and observation tower located in Downtown Toronto, Ontario, Canada. Built on the former Railway Lands, it was completed in 1976. Its name “CN” originally referred to Canadian National, the railway company that built the tower.

The CN Tower held the record for the world’s tallest free-standing structure for 32 years until 2007 when it was surpassed by the Burj Khalifa. It is now the ninth tallest free-standing structure in the world and remains the tallest free-standing structure in the Western Hemisphere. In 1995, the CN Tower was declared one of the modern Seven Wonders of the World by the American Society of Civil Engineers.