Algueirão – Mem Martins (Portuguese pronunciation: [aɫɡɐjˈɾɐ̃w̃ ˈmɐ̃ȷ̃ mɐɾˈtĩʃ]) is a Portuguese civil parish, in the municipality (concelho) of Sintra. The population in 2011 was 66,250, in an area of 16.00 km². it has a population density of about 4000 inhabitants per kilometer square (and is one of the most densely populated parishes in Portugal). It was elevated from the status of village to town on 1 February 1988.