Its construction was initiated in 1120 and dedicated to the cult in 1225 by Bishop Egea, in times of Alfonso IX .

It rises on the highest part of the city , preserving the appearance of Fortaleza with crenellated towers , passageways and corridors .

Its architectural foundation belongs to the Romanesque style, which was later added as a finishing Gothic work .

This second style is well represented in the entrance porch , first Gothic work that was done in the Iberian Peninsula.

Inside you can admire the Sacrament Chapel , the chapel , the chapel of San Telmo , the choir , one of the most important collections owned by the cathedral of Tui , the museum before chapel of Santa Catalina , plain, unformatted , chapel Sacramento , organ and cloister.