It is attributed to the Castle of Óbidos Roman origin, probably based in a castro. It was later fortification under Arab rule. After conquered by Christians (1148) it was repaired and expanded several times. In the reign of D. Manuel I, his governor orders to build a palace and alter some parts of the castle. In the Palace of the Alcaides the windows of beautiful Manueline cut open to the interior of the patio. The chimney in the main room and the portal surmounted by the royal arms and the Noronha family, flanked by two armillary spheres, still belong to his time. The Palace suffered heavy damage from the earthquake of 1755. In the 20th century it was in complete ruin and recovered to install the Pousada (the first state inn in historical building).
The castle and the entire urban area of Óbidos village are classified as a national monument.