Hong Kong, officially the Hong Kong Special Administrative Region of the People's Republic of China is a city and a special administrative region in China.   Hong Kong is one of the most densely populated territories in the world.   Hong Kong was established as a colony of the British Empire after the Qing Empire ceded Hong Kong Island in 1841–1842.   The colony expanded to the Kowloon Peninsula in 1860 and was further extended when the United Kingdom obtained a 99-year lease of the New Territories in 1898.   Hong Kong was briefly occupied by Japan from 1941 to 1945 during World War II.   The whole territory was transferred from the United Kingdom to China in 1997.   Hong Kong maintains separate governing and economic systems from that of mainland China under the principle of "one country, two systems".

Originally a sparsely populated area of farming and fishing villages, the territory is now one of the world's most significant financial centres and commercial ports.   Hong Kong is the world's fourth-ranked global financial centre, ninth-largest exporter, and eighth-largest importer.   Its currency, the Hong Kong dollar, is the eighth most traded currency in the world. Home to the second-highest number of billionaires of any city in the world, Hong Kong has the largest concentration of ultra high-net-worth individuals.   Although the city has one of the highest per capita incomes in the world, severe income inequality exists among the population.   Despite having the largest number of skyscrapers of any city in the world, housing in Hong Kong has been well-documented to experience a chronic persistent shortage.

Hong Kong is on China's southern coast, 60 km (37 mi) east of Macau, on the east side of the mouth of the Pearl River estuary.   It is surrounded by the South China Sea on all sides except the north, which neighbours the Guangdong city of Shenzhen along the Sham Chun River.   The territory's 1,110.18 square km (428.64 square mi) area (2,754.97 square km if the maritime area is included) consists of Hong Kong Island, the Kowloon Peninsula, the New Territories, Lantau Island, and over 200 other islands.   The territory's highest point is Tai Mo Shan, 957 metres (3,140 ft) above sea level.   Urban development is concentrated on the Kowloon Peninsula, Hong Kong Island, and in new towns throughout the New Territories.   Much of this is built on reclaimed land from the sea.   Undeveloped terrain is hilly to mountainous, with very little flat land, and consists mostly of grassland, woodland, shrubland, or farmland.   About 40% of the remaining land area is country parks and nature reserves.

Hong Kong has the world's largest number of skyscrapers, with 482 towers taller than 150 metres (490 ft), and the third-largest number of high-rise buildings in the world.   The lack of available space restricted development to high-density residential tenements and commercial complexes packed closely together on buildable land.   Single-family detached homes are uncommon and generally only found in outlying areas.   The International Commerce Centre and Two International Finance Centre are the tallest buildings in Hong Kong and are among the tallest in the Asia-Pacific region.   Other distinctive buildings lining the Hong Kong Island skyline include the HSBC Main Building, the anemometer-topped triangular Central Plaza, the circular Hopewell Centre, and the sharp-edged Bank of China Tower.