Macau and also spelled Macao and officially the Macao Special Administrative Region of the People's Republic of China, is a special administrative region on the western side of the Pearl River estuary in southern China. With a population of 667,400 and an area of 32.9 km2 (12.7 sq mi), it is the most densely populated region in the world.
Macau was formerly a colony of the Portuguese Empire, after Ming China leased the territory as a trading post in 1557. Between 1557 and 1887, Macau was governed by the Portuguese under Chinese authority and sovereignty. In 1887, Portugal was given perpetual colonial rights for Macau which gave Portuguese sovereignty over Macau. The colony remained under Portuguese rule until 1999, when it was transferred to China. As a special administrative region, Macau maintains separate governing and economic systems from that of mainland China.
Originally a sparsely populated collection of coastal islands, the territory has become a major resort city and the top destination for gambling tourism. It is the ninth-highest recipient of tourism revenue and its gambling industry is seven times larger than that of Las Vegas, Although the city has one of the highest per capita incomes in the world, it has severe income inequality. Its GDP per capita by purchasing power parity is one of the highest in the world and higher than any country in the world in 2014 according to the World Bank.
Macao has the fourth-highest life expectancy in the world. The territory is highly urbanized and most development is built on reclaimed land.