The CN Tower is a communications and observation tower in Downtown Toronto. Standing 553.33m (1,815.4ft) tall, it was completed in 1976, becoming the world’s tallest free-standing structure and world’s tallest tower at the time. It held both records for 34 years until the completion of Burj Khalifa and Canton Tower in 2010. It remains the tallest free-standing structure in the Western Hemisphere, a signature icon of Toronto’s skyline, and a symbol of Canada, attracting more than two million international visitors annually.
Its name “CN” originally referred to Canadian National, the railway company that built the tower. Following the railway’s decision to divest non-core freight railway assets, prior to the company’s privatization in 1995, it transferred the tower to the Canada Lands Company, a federal Crown corporation responsible for real estate development. Since the name CN Tower became common in daily usage, the abbreviation was eventually expanded to Canadian National Tower or Canada’s National Tower. However, neither of these names is commonly used.
In 1995, the CN Tower was declared one of the modern Seven Wonders of the World by the American Society of Civil Engineers. It also belongs to the World Federation of Great Towers, where it holds second-place ranking.
The CN Tower opened to the public on June 26, 1976, although the official opening date was October 1, 1976. The construction costs of approximately CDN$63 million ($243 million in 2012 dollars) were repaid in fifteen years. Canadian National Railway sold the tower prior to taking the company private in 1995, when they decided to divest themselves of all operations not directly related to their core freight shipping businesses.
As the area around the tower was developed, particularly with the introduction of the Metro Toronto Convention Centre in 1984 and the SkyDome in 1989 (renamed Rogers Centre in 2005), the former Railway Lands were redeveloped and the tower became the centre of a newly developing entertainment area. Access was greatly improved with the construction of the SkyWalk in 1989, which connected the tower and SkyDome to the nearby railway and subway station, Union Station and, in turn, to the city’s PATH underground pedestrian system. By the mid-1990s, it was the centre of a thriving tourist district. The entire area continues to be an area of intense building, notably a boom in condominium construction in the 2000s and the 2010s.
When the CN Tower opened in 1976, there were three public observation points: the Space Deck (now renamed SkyPod) at 447m, the Indoor Observation Level (now named Indoor Lookout Level) at 346 m, and the Outdoor Observation Terrace (at the same level as the current Glass Floor) at 342 m.
On June 26, 1986, the ten-year anniversary of the tower’s opening, high-rise firefighting and rescue advocate Dan Goodwin, in a sponsored publicity event, used his hands and feet to climb the outside of the tower, a feat he performed twice on the same day. Following both ascents, he used multiple rappels to descend to the ground.
The Glass Floor (at an elevation of 342 m) opened to the public on June 26, 1994.
From 1997 to January 2004, TrizecHahn Corporation managed the tower and instituted several expansion projects including a $26 million entertainment expansion and revitalization that included the 1997 addition of two new elevators (to a total of six) and the relocation of the staircase from the north side leg to inside the core of the building, a conversion that also added nine stairs to the climb.
In 2007, light-emitting diode (LED) lights replaced the incandescent lights that lit the CN Tower at night, the reason cited that LED lights are more cost and energy efficient than the incandescent lights. The colour of the LED lights can change, compared to the constant white colour of the incandescent lights.
On September 12, 2007, Burj Khalifa, then under construction, surpassed the CN Tower as the world’s tallest free-standing structure.
In 2008, glass panels were installed in one of the CN Tower elevators, which established a world record (346m) for highest glass floor paneled elevator in the world.
The CN Tower was closed during the G-20 summit on June 26–27, 2010, for security reasons, given its proximity to the Metro Toronto Convention Centre.
On August 1, 2011, the CN Tower opened the EdgeWalk, an amusement in which thrill-seekers can walk on and around the roof of the main pod of the tower at 356m (1,168.0ft), which is directly above the 360 Restaurant. It is the world’s highest full-circle, hands-free walk. Visitors are tethered to an overhead rail system and walk around the edge of the CN Tower’s main pod above the 360 Restaurant on a 1.5-metre (4.9ft) metal floor. The attraction is closed throughout the winter season and during periods of electrical storms and high winds.
Source: http://en.wikipedia.org/wiki/CN_Tower