Built in the late 12C, shortly after the city had been captured by Afonso Henriques, the cathedral (like those in Oporto, Coimbra and Évora) was also a formidable fortress and has been remodelled on several occasions. One of its chapels houses the 14C Gothic tombs of Lopo Fernandes Pacheco, comrade in arms of King Afonso IV, and his wife. The fine treasury displays an array of magnificent religious artefacts.