Alcobaça (Portuguese pronunciation: [ɐɫkuˈβasɐ]) is a city in Alcobaça Municipality in Oeste Subregion and Leiria District, 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 has a total population of 55,269 inhabitants and a total area of 408.1 km². The city itself has a population of 15,800 inhabitants.