CN Tower

The CN Tower (French: Tour CN) is a tall 553.3 m-high (1,815.3 ft) tower in Toronto, Ontario, Canada. It was finished in 1976 and stands in downtown Toronto on the old Railway Lands. Its name "CN" means Canadian National, the railway company that built it.

For many years, the CN Tower was the world's tallest free-standing structure. It kept this record for 32 years, from 1975 until 2007. After that, it was taller than the Burj Khalifa. It is still a famous landmark and one of the modern Seven Wonders of the World, as chosen by the American Society of Civil Engineers.

Today, the CN Tower is a well-known symbol of Toronto's skyline. Many people visit each year. They come to see the observation decks, a special revolving restaurant high above the ground, and other fun things to do.

History

The CN Tower was first imagined in 1968 when the Canadian National Railway wanted to build a tall tower for television and radio signals in Toronto. They wanted to show how strong Canadian industry was. As Toronto grew, new tall buildings made it hard for radio and television signals to reach everyone well. The tower would help solve this problem.

Construction of the CN Tower began in 1973. Workers dug deep into the ground to build strong foundations and then built the tall tower using special methods. The tower opened to the public on June 26, 1976. It became one of the most famous landmarks in Toronto and attracted many visitors. Over the years, new attractions like a glass floor and a walk around the edge of the tower were added to entertain people.

Closures

The CN Tower was closed on September 11, 2001, after big events happened in New York City. It was also closed during a big meeting of leaders in June 2010 for safety reasons. The tower stayed closed from 2020 to 2021 because of health rules during a sickness spreading around the world. One day in December 2021, the tower had to close because glass was falling off in strong winds.

Structure

The CN Tower has several parts. The main part is a tall, hollow concrete pillar shaped like a hexagon. Inside this pillar are stairwells and pipes for electricity and water. The tower has six elevators with glass walls, so you can see the city as you ride up.

At the top of the concrete part is a very tall metal antenna. This antenna sends out TV and radio signals. There are three places where visitors can go:

the Lower Observation Level, which has a special glass floor and an outdoor area,
the Main Observation Level, and
The Top, which is just below the antenna.

View straight down from the SkyPod to the roof of the Observation Level

The tower’s shape changes near the top, and below the main levels, there are three big legs that make it look like a tripod.

The main level of the tower has seven floors, some of which are open to the public. Below the public areas is a large round structure that holds transmitters. The glass floor can hold a lot of weight and has special thermal glass that keeps it warm. There is also a restaurant that slowly turns around as you eat.

The Top used to be the highest place you could go in the world, but another tall building in Shanghai passed it in height in 2008.

There is a very tall metal staircase inside the tower, used mostly for emergencies or special events. It has over 1,700 steps to reach the main level and more than 2,500 steps to reach The Top. It is the tallest metal staircase in the world.

Architects

WZMH Architects
John Hamilton Andrews
Webb Zerafa
Menkes Housden with the help of Edward R. Baldwin

Safety features

After a fire in a similar tower in Moscow, officials checked the CN Tower carefully. They found that the CN Tower has many safety features to prevent fires, like fireproof materials, frequent inspections, a good sprinkler system, and special water tanks at the top. There is also a special elevator that can work during a fire and is powered by generators at the base. These safety measures help keep the tower safe.

The CN Tower has had a very good safety record, with only one small electrical fire in its antennas in 2017, which was the tower’s first fire. Other tall buildings built around the same time also have strong safety records.

Lighting

The CN Tower is lit up at night with special lights. The original lights were replaced in 1997 because they used too much energy. In 2007, the tower got new, bright LED lights that shine from dusk until 2 a.m. These lights use less energy and can change colors for special events.

The tower’s lights change colors for holidays and important moments. After big sports events, it might show the colors of the winning team. It has also shown the colors of flags from other countries to honor special people or events. The lights are controlled from a computer far away.

During spring and fall when birds are flying, the lights are turned off to help keep birds safe. This is part of a program that asks tall buildings to dim their lights during busy bird travel times.

Date	Colour	Occasion
Ongoing	Red and white	Top of the hour CN Tower light show
January 26	Light blue and yellow	World Alzheimer Day
February 4	Orange and blue	World Cancer Day
February 14	Red	Valentine's Day
March 17	Green	Saint Patrick's Day
March 21–June 20	Decreased lighting	Bird migration – Lighting is decreased during spring bird migration
September 23–December 20	Decreased lighting	Bird migration – Lighting is decreased during autumn bird migration
December	Red and green	Season's Greetings
December 1	Red	World AIDS Day
December 6	Purple	White Ribbon Day
December 10	Yellow	Human Rights Day
December 21	Blue and white	Winter solstice
December 31	Countdown to New Year's Eve and light show	New Year's Eve

Height comparisons

The CN Tower is the tallest freestanding structure in the Western Hemisphere. As of 2013, two other structures in the Western Hemisphere were taller than 500 m: the Willis Tower in Chicago and One World Trade Center in New York City. The CN Tower was the tallest freestanding structure in the Western Hemisphere for many years.

There has been some debate about whether the CN Tower is the "world's tallest tower" or the "world's tallest building." Organizations like Guinness World Records have different ways to define these titles. The CN Tower does not have floors all the way from the ground up, so some groups call it a "tower" instead of a building. Other tall structures, like radio masts, are not "free-standing" because they are supported by wires. The CN Tower was the tallest freestanding structure in the world until 2007 when Burj Khalifa in Dubai became taller. Even after that, the CN Tower still holds several records, such as the highest wine cellar and restaurant above ground.

Record	Owner	Value	Time period	Succeeded by
World's tallest free-standing structure	CN Tower	553.33 metres (1,815.4 ft)	March 31, 1975 to September 12, 2007	Burj Khalifa
World's tallest tower	CN Tower	553.33 metres (1,815.4 ft)	1975 to 2009	Canton Tower
World's highest public observation gallery	The Top	447 metres (1,467 ft)		Canton Tower
World's highest glass floor panelled elevator	CN Tower	346 metres (1,135 ft)	2008 to present	—
World's longest metal staircase	CN Tower	2,579 steps
World's highest glass floor	CN Tower	342 metres (1,122 ft)	2008 to July 2, 2009	Willis Tower
World's highest and largest revolving restaurant	360 Restaurant	351 metres (1,152 ft)
World's highest bar	Horizons Restaurant	346 metres (1,135 ft)	September 21, 2009 to present	—
World's highest wine cellar	360 Restaurant	351 metres (1,152 ft)

Use

The CN Tower is an important communications tower for many media companies and services.

FM radio transmitters sit in a tall metal antenna on top of the tower, high above the ground.

Bell Canada
Toronto Transit Commission
Amateur radio repeaters "2-Tango" (VHF) and "4-Tango" (440/70 cm UHF)—owned and operated by the Toronto FM Communications Society, under callsign VE3TWR

VHF	UHF	Virtual	Callsign	Affiliation	Branding
9	—	9.1	CFTO-DT	CTV	CTV Toronto
—	19	19.1	CICA-DT	TVO	TVO
—	20	5.1	CBLT-DT	CBC Television	CBC Toronto
—	25	25.1	CBLFT-DT	Ici Radio-Canada Télé	ICI Ontario
—	40	40.1	CJMT-DT	Omni Television	Omni Television
—	41	41.1	CIII-DT	Global	Global Toronto
—	44	57.1	CITY-DT	Citytv	Citytv Toronto
—	47	47.1	CFMT-DT	Omni Television	Omni Television
Source: Vividcomm

Frequency	kW	Callsign	Affiliation/Owner	Branding
91.1 MHz	40	CJRT	Independent; Public	JAZZ.FM91
94.1 MHz	38	CBL	Canadian Broadcasting Corporation	CBC Music
97.3 MHz	28.9	CHBM	Stingray Group	boom 97.3
98.1 MHz	44	CHFI	Rogers Sports & Media	98.1 CHFI
99.9 MHz	40	CKFM	Bell Media	Virgin Radio 99.9FM
100.7 MHz	4	CHIN	CHIN Radio/TV International	CHIN Radio
102.1 MHz	35	CFNY	Corus Entertainment	102.1 the Edge
104.5 MHz	40	CHUM	Bell Media	104.5 CHUM FM
107.1 MHz	40	CILQ	Corus Entertainment	Classic Rock Q 107
Source: Vividcomm

In popular culture

The CN Tower has been in many movies, TV shows, music, and video games. It even has a special mascot that looks like the tower.

Some examples include the 1982 movie Highpoint, the 2016 album Views by Drake, and the 2025 film Nirvanna the Band the Show the Movie. These shows and songs feature the tower in fun and creative ways.