1 Toronto is the fifth largest city in North America
Larger cities include Mexico City, New York City, Los Angeles and Chicago.
Now it's the third
2 Toronto's PATH is the largest underground pedestrian system in North America. PATH is 29 km (18 mi) long and connects 1200 stores and restaurants, 50 office towers, 20 parking garages, 5 subway stations, 6 hotels, and a railway terminal
PATH is also known as the underground city - it's a network of pedestrian tunnels beneath Downtown Toronto.
According to Guinness World Records, PATH is the largest underground shopping complex in the world with 371,600 m² of retail space.
3 Toronto's CN Tower held the record for the World's tallest tower for 34 years, from 1975 to 2009, when it was overtaken by the Canton Tower in Guangzhou, China
I made a list about the CN Tower, with many images and details - Top 10 Interesting Facts About the CN Tower in Toronto, Canada
4 The Rogers Centre is the first stadium in the world to have a fully retractable roof
The image shows the stadium with roof closed and roof opened
5 Around 25% of the Hollywood movies are actually filmed in Toronto
6 Toronto's Casa Loma is the only truly authentic castle in North America
7 Toronto is the capital city of the province of Ontario and not of Canada
This is a very common mistake - many people think Toronto is the capital of Canada but the capital of Canada is Ottawa
8 Toronto has over 1,500 parks (which take up 18.1% of the city's total area) and over 10 million trees
Toronto is a very "green city" - with many parks and "green belts".
9 The Toronto Islands, just a short ferry ride away from downtown Toronto, comprise the largest urban car-free community in North America
10 The Toronto Maple Leafs is one of the worst teams in the NHL - they haven’t won a Stanley Cup since 1967. Despite this, they have a loyal fan base and tickets are always sold out
I added this just to show I am not completely biased and I can admit some disadvantages :-)
The Contenders
11 Toronto has the second largest public transit system in North America
12 Almost 25% of Canada's population lives within a 160 km radius of Toronto
13 Toronto is the second most business friendly city in the world after Hong Kong
Cool, and here I was, thinking of Miami
14 Toronto has at least 3 universities and 5 community colleges
15 Pope John Paul II visited Toronto twice
The first time was in 1984, and the second time was in 2002.
16 Toronto has the largest population of Italians outside of Italy
17 Toronto is home to 8,100 restaurants and bars
18 Over 180 languages and dialects are spoken in the city
19 Toronto has over 9,000 streets
20 Toronto International Film Festival (TIFF) is widely noted as the second most prestigious in the world, only behind Cannes
Established in 1976, TIFF was originally called the "Festival of Festivals" (it sounds funny to me now)
21 There are around 160 completed skyscrapers and over 100 are being constructed
22 Toronto covers an area of 641 square kilometres, stretching 43 km from east to west, and 21 km from north to south