Macau or Macao is a special administrative region of the People's Republic of China. With a population of about 680,000 and an area o…Macau or Macao is a special administrative region of the People's Republic of China. 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 by the Ming dynasty as a trading post in 1557. Portugal paid an annual rent and administered the territory under Chinese sovereignty until 1887.