Alcobaça (Portuguese pronunciation: [ɐɫkuˈβasɐ]) is a city and a municipality in Oeste Subregion, region Centro in Portugal, formerly included in the Estremadura Province. The city grew along the valleys of the rivers Alcoa and Baça, from which it derives its name. The municipality population in 2011 was 56,693, in an area of 408.14 km².