Le monastère de Santa Maria d'Alcobaça, au nord de Lisbonne, Portugal, est fondé au XIIᵉ siècle par le roi Alphonse Iᵉʳ. Par l'ampleur de ses dimensions, la clarté du parti architectural, la beauté du matériau et le soin apporté à l'exécution, il est considéré comme un chef-d'œuvre de l'art gothique cistercien

The first architect(s) of the church, most probably of French origin, followed the design of the Abbey of Clairvaux (now mostly demolished), which had been founded by Bernard of Clairvaux in 1115. The church is a Latin-cross building with pronounced transept arms and three aisles. The lateral aisles of the nave are as high (20 metres) as the central one, which together with the relative slenderness of the church (17 metres) and large length (106 metres) conveys an impression of monumentality. Alcobaça remains, after 800 years, the largest Portuguese church. The vertical emphasis observed in the building is a typical gothic feature.

Columns and walls are devoid of decoration, as required in Cistercian churches, and the interior is very brightly illuminated by rows of windows on the walls and rose windows on the main façade and transept arms. The main chapel, like in Clairvaux, is surrounded by a gallery (ambulatory) and has a series of radiating chapels. The aisles are covered by simple Gothic vaulting.

Kitchen
The kitchen of the monastery was built and covered with tiles in the mid-18th century. The central chimney is enormous, supported by eight iron columns. Water and fresh fish were diverted from the river Alcoa to the kitchen basin through a specially built canal.