The Cathedral (Se) was built on a site where religious buildings had already been built for centuries. At first there was a Roman temple here, which was turned into a church in the 6th century. A couple of centuries later, the Moors built a mosque, which stood here until the 12th century. After the siege and liberation of Lisbon from the Moors, the mosque was destroyed and the Cathedral was built in its place.
The cathedral building resembles a fortress. The two large, massive bell towers have loopholes for archery. The towers also served as observation points in turbulent times. Their thick walls were completely devoid of windows in their lower parts, making them invulnerable to enemy attacks. It was thanks to the strong walls that the cathedral withstood the destructive force of the 1755 earthquake.
The main part of the medieval building has been preserved, requiring minor alterations and minimal restoration. A large rose window, a massive entrance portal with round archivolts, and twin towers with a beautiful arcade of upper tiers adorn the western facade of the building.
The interior of the cathedral is sombre and severe. In the inner gallery are nine Gothic chapels housing the remains of great Portuguese, including those of King Alfonso IV and his wife Beatriz. At the entrance to the cathedral, on the left, is a small chapel where the future Franciscan monk, St Anthony, was baptised.
The cathedral's treasury contains priestly vestments, silverware, sculptures, medieval manuscripts and sacred relics.
