Hong Kong (Chinese: "Fragrant Harbour" "Incense Harbour"), officially the Hong Kong Special Administrative Region of the People's Republic of China, is an autonomous territory on the Pearl River Delta of East Asia. Macau lies across the delta to the west, and the Chinese province of Guangdong borders the territory to the north. With a total land area of 1,106 square kilometres (427 sq mi) and a population of over 7.3 million of various nationalities, it ranks as the world's fourth most densely populated sovereign state or territory.

London is the capital and most populous city of England and the United Kingdom. Standing on the River Thames in the south east of the island of Great Britain, London has been a major settlement for two millennia. It was founded – probably close to an already existing Celtic Briton village or settlement – around the year 43 by the Romans, who named it Londinium. London's ancient core, the City of London, largely retains its 1.12-square-mile (2.9 km2) medieval boundaries. Since at least the 19th century, "London" has also referred to the metropolis around this core, historically split between Middlesex, Essex, Surrey, Kent, and Hertfordshire, which today largely makes up Greater London, governed by the Mayor of London and the London Assembly.

The City of New York, often called New York City or simply New York, is the most populous city in the United States. Located at the southern tip of the state of New York, the city is the center of the New York metropolitan area, one of the most populous urban agglomerations in the world. With a U.S. Census Bureau-estimated 2015 population of 8,550,405 distributed over a land area of just 305 square miles (790 km2), New York is also the most densely populated major city in the United States. A global power city, New York City exerts a significant impact upon commerce, finance, media, art, fashion, research, technology, education, and entertainment, its fast pace defining the term New York minute. Home to the headquarters of the United Nations, New York is an important center for international diplomacy and has been described as the cultural and financial capital of the world.

Paris is the capital and the most populous city of France. It has an area of 105 square kilometres (41 square miles) and a population in 2013 of 2,229,621 within the administrative limits. The city is both a commune and department, and forms the centre and headquarters of the Île-de-France, or Paris Region, which has an area of 12,012 square kilometres (4,638 square miles) and a population in 2014 of 12,005,077, comprising 18.2 percent of the population of France.

Tokyo, officially Tokyo Metropolis,is one of the 47 prefectures of Japan, and is both the capital and most populous city of Japan. The Greater Tokyo Area is the most populous metropolitan area in the world. It is the seat of the Emperor of Japan and the Japanese government. Tokyo is in the Kantō region on the southeastern side of the main island Honshu and includes the Izu Islands and Ogasawara Islands. Formerly known as Edo, it has been the de facto seat of government since 1603 when Shogun Tokugawa Ieyasu made the city his headquarters. It officially became the capital after Emperor Meiji moved his seat to the city from the old capital of Kyoto in 1868; at that time Edo was renamed Tokyo. Tokyo Metropolis was formed in 1943 from the merger of the former Tokyo Prefecture and the city of Tokyo.

Toronto 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 fifth largest city in North America. A population estimate from a city report released in 2013 shows the city is now the fourth most populous city in North America, after Mexico City, New York City, and Los Angeles. An established global city, Toronto is an international centre of business, finance, arts, and culture, and widely recognized as one of the most multicultural and cosmopolitan cities in the world.