Sé do Porto
Sé do Porto - 4000 Porto
This Romanesque style construction began in the twelfth century. Several changes up until the twentieth century did not quite manage to lessen its somewhat primitive austerity. The sacristy, cloister and the beautiful blue (azulejo) tiles that cover its galleries, as well as the chapel, date from the Gothic period. A beautiful 13th century rosace stands out on the west front. The paintings by Nasoni, the carved gilded wood altarpiece and the silver altar of the Blessed Sacrament are all noteworthy. Mass is still celebrated there but if it is tranquility which you seek, do not miss the cloister.
Reckon on paying 3 euros per person for the visit. Sé Catedral is also a great place to get a 360 degrees view of Porto.