Macau, often known as Macao, is a Chinese city and special administrative zone located in the western Pearl River Delta near the South China Sea. It is the world's most densely inhabited location, with a population of over 680,000 people and an area of 32.9 km2 (12.7 sq mi).
The land of Portuguese Macau, once a Portuguese colony, was originally leased to Portugal as a trade station by the Ming dynasty in 1557. Up until 1887, Portugal paid an annual fee and controlled the region under Chinese rule. The Sino-Portuguese Treaty of Peking granted Portugal permanent colonial rights. The colony was under Portuguese control until 1999, when it was handed up to China. Macau is a Chinese special administrative territory that maintains distinct governance and economic systems from the rest of the nation under the idea of "one country, two systems." The city's historic center was included on the UNESCO World Heritage List in 2005 due to its unique combination of Portuguese and Chinese architecture.
Originally a thinly inhabited collection of coastal islands, Macau has evolved into a major resort city and a leading casino tourist destination, with a gaming industry seven times greater than that of Las Vegas. The city has one of the greatest per capita incomes in the world, as well as one of the highest GDP per capita by buying power parity. It boasts the world's fourth-highest life expectancy and a very high Human Development Index, according to the Macau government. The region is densely populated; two-thirds of the total land area is developed on the sea-reclaimed ground.