Macau

Macau or Macao, officially the Macao Special Administrative Region of the People's Republic of China, is a city and special administrative region of China in the western Pearl River Delta by the South China Sea. With a population of about 680,000 and an area of 32.9 km2, it is the most densely populated region in the world.

Formerly a Portuguese colony, the territory of Portuguese Macau was first leased to Portugal as a trading post by the Ming dynasty in 1557. Portugal paid an annual rent and administered the territory under Chinese sovereignty until 1887. Portugal later gained perpetual colonial rights in the Sino-Portuguese Treaty of Peking.