CN Tower is a concrete communications and observation tower located in Downtown Toronto, Canada. Built in 1976, it stands 553.3 meters high, which made it the tallest tower and the tallest freestanding structure in the world, a record it held for 32 years until 2007, when the Burj Khalifa overtook it. It is the signature icon of Toronto’s skyline and the most recognizable architectural symbol of Canada. Its iconic nature is further evidenced by the fact that in 1995 the American Society of Civil Engineers included it in the Seven Wonders of the Modern World.
The reasons behind its construction stemmed from very practical concerns about communications and networks that had suffered due to the boom of tall buildings in the city, thus it was required to build a tower with a tall enough antenna that it would not receive any interference from nearby architecture. During the design the architects added the observation deck and a revolving restaurant to the plans, thus ending up with the iconic form that we see today. The usable floor space area is comprised of seven levels near the top with the antenna placed at the pinnacle.
This space includes three main areas open to visitors. The first located at an altitude of 342 meters is the Glass Floor and the Outdoor Observation Deck (Exterior Observation Platform). The Glass Floor is an indoor area from which you can see the 342 meters that fall under the glass plates forming the floor and the terrace outside the Tower. Outdoor Observation Deck is a viewpoint from where visitors can experience unobstructed views of the city At 346 meters is the Lookout Level, which is located in the Café Horizon and contains another observation deck inside. At 351 meters high is located a restaurant which rotates 360 ° every 72 minutes. The third area to which the public has access is the Skypod, at 447 meters, one of the highest public vantage points in the world.
The CN Tower is composed of several structures. The main structure is a hexagonal hollow pillar of steel and concrete containing all six elevators, escalators, connections and power distribution. At the top of this tower is a metallic antenna signal transmission for radio and television. The hexagonal shape of the tower can be seen between the two areas for visitors, but off the main platform, three support legs give the tower the appearance of a large tripod.
Though it is no longer the tallest tower in the world, it still holds an iconic status in architectural and engineering and is host to almost two million visitors annually.