In the center of Faro, in the Old Town, stands the cathedral. It was erected in the 13th century on the site of an ancient mosque, which, in turn, grew on the site of the Roman Forum. All around stretches a large square of irregular shape, planted with orange trees, which greatly enliven the landscape with their fragrant flowers and bright fruits. Much of the original Gothic church was destroyed in the 1755 earthquake and rebuilt later. From the old building, the tower and windows of the south side have been preserved.

Now the Cathedral is a mixture of Gothic, Renaissance and Baroque elements. The interior decoration is light, even similar in style to a basilica. The nave has three aisles, almost imperceptibly separated from each other by slender columns, there are good examples of baroque carving and bright stained glass windows. The cathedral is crowned with a vaulted ribbed tiled roof.

In the Capel di Santo Lenjo, to the right of the altar, is the tomb of António Pereira da Silva, Bishop of the Algarve from 1704 to 1715.