CN Tower

The CN Tower (French: Tour CN) is a 553.33 m-high (1,815.4 ft) concrete communications and observation tower in downtown Toronto, Ontario, Canada. Built on the former Railway Lands, 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 is now the 3rd tallest tower in the world and 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.

Tower

A tower is a tall structure, taller than it is wide, often by a significant margin. Towers are distinguished from masts by their lack of guy-wires and are therefore, along with tall buildings, self-supporting structures.

Towers are specifically distinguished from "buildings" in that they are not built to be habitable but to serve other functions. The principal function is the use of their height to enable various functions to be achieved including: visibility of other features attached to the tower such clock towers; as part of a larger structure or device to increase the visibility of the surroundings as in a fortified building such as a castle; or as a structural feature as an integral part of a bridge.

Towers can be stand alone structures or be supported by adjacent buildings or can be a feature on top of a large structure or building.

History

Towers have been used by mankind since prehistoric times. The oldest known may be the circular stone tower in walls of Neolithic Jericho (8000 BC). Some of the earliest towers were ziggurats, which existed in Sumerian architecture since the 4th millennium BC. The most famous ziggurats include the Sumerian Ziggurat of Ur, built the 3rd millennium BC, and the Etemenanki, one of the most famous examples of Babylonian architecture. The latter was built in Babylon during the 2nd millennium BC and was considered the tallest tower of the ancient world.

Toronto

Toronto (ⁱ/təˈrɒntoʊ, -tə/,local /təˈrɒnoʊ, ˈtrɒ-/) is the most populous city in Canada, the provincial capital of Ontario, and the centre of the Greater Toronto Area, the most populous metropolitan area in Canada. In the 2011 census, Toronto had a population of 2,615,060, making it the fourth most populous city in North America, after Mexico City, New York City, and Los Angeles. An alpha global city, Toronto is an international centre of business, finance, arts, and culture, and is widely recognized as one of the most multicultural and cosmopolitan cities in the world.

Aboriginal peoples have inhabited the area now known as Toronto for thousands of years. The urban history of the city dates back to 1787, when British officials negotiated the Toronto Purchase with the Mississaugas of the New Credit. They established the Town of York, and later designated it as the capital of Upper Canada. During the War of 1812, the town was the site of the Battle of York and suffered heavy damage by U.S. troops. York was renamed and incorporated as the City of Toronto in 1834, and became the capital of the province of Ontario in 1867. The original borders of Toronto were expanded through amalgamation with surrounding municipalities at various times in its history, the results of which can been seen in the 140 independently unique and clearly defined official neighbourhoods that make up the city.

Canada

Coordinates: 60°N 95°W / 60°N 95°W / 60; -95

Canada (ⁱ/ˈkænədə/; French: [ka.na.da]) is a country in the northern part of North America. Its ten provinces and three territories extend from the Atlantic to the Pacific and northward into the Arctic Ocean, covering 9.98 million square kilometres (3.85 million square miles), making it the world's second-largest country by total area and the fourth-largest country by land area. Canada's border with the United States is the world's longest land border. Canada is sparsely populated, the majority of its land territory being dominated by forest and tundra and the Rocky Mountains; about four-fifths of the country's population of 35 million people live near the southern border. The majority of Canada has a cold or severely cold winter climate, but southerly areas are warm in summer.

The land now called Canada has been inhabited for millennia by various Aboriginal peoples. Beginning in the 15th century, British and French colonies were established on the Atlantic coast, with the first establishment of a region called "Canada" occurring in 1537. As a consequence of various conflicts, the United Kingdom gained and lost territories within British North America until left, in the late 18th century, with what mostly geographically comprises Canada today. Pursuant to the British North America Act, on July 1, 1867, the colonies of Canada, New Brunswick, and Nova Scotia joined to form the autonomous federal Dominion of Canada. This began an accretion of provinces and territories to the self-governing Dominion to the present ten provinces and three territories forming modern Canada. In 1931, Canada achieved near total independence from the United Kingdom with the Statute of Westminster 1931, and full sovereignty was attained when the Canada Act 1982 removed the last remaining ties of legal dependence on the British parliament.

Ontario

Ontario (ⁱ/ɒnˈtɛərioʊ/) is one of the ten provinces of Canada, located in east-central Canada. It is Canada's most populous province by a large margin, accounting for nearly 40 percent of all Canadians, and is the second largest province in total area. Ontario is fourth largest in total area when the territories of the Northwest Territories and Nunavut are included. It is home to the nation's capital city, Ottawa, and the nation's most populous city, Toronto.

Ontario is bordered by the province of Manitoba to the west, Hudson Bay and James Bay to the north, and Quebec to the east, and to the south by the US states of (from west to east) Minnesota, Michigan, Ohio, Pennsylvania and New York. All of Ontario's 2,700 km (1,678 mi) border with the United States follows inland waterways: from the west at Lake of the Woods, eastward along the major rivers and lakes of the Great Lakes/Saint Lawrence River drainage system. These are the Rainy River, the Pigeon River, Lake Superior, the St. Marys River, Lake Huron, the St. Clair River, Lake St. Clair, the Detroit River, Lake Erie, the Niagara River, Lake Ontario and along the St. Lawrence River from Kingston, Ontario, to the Quebec boundary just east of Cornwall, Ontario.