Tui Cathedral is a remarkable building: a 12th-century Romanesque church that was given a Gothic facade, fortified against warfare, and has somehow remained in active use ever since. The Romanesque interior — heavy stone columns, barrel-vaulted nave, the quiet darkness of a medieval church — contrasts with the Gothic portal outside, where carved figures in the French manner stand in rows above the main entrance.
The cloister on the southern side is the most peaceful part of the complex — a large, grass-filled square surrounded by Gothic arcades, with views over the rooftops of the lower town and the river valley. The cathedral museum contains some good pieces of medieval religious art. The cathedral is the starting point for any exploration of Tui's old town, and the hilltop around it gives excellent views in all directions.