This cathedral is a complex building from an architectural point of view since it combines a great variety of styles. The main structure dates from the 13th century, but the church was seriously remodelled in the 19th century. The massive bell tower-porch is undoubtedly the oldest part. The first two levels are medieval, and the last seems to date from the 17th century. In the 19th century, it was decorated with brick arches and topped by a cornice, additions which compromised its original austerity.
The most remarkable object inside the church is a tall Eucharist tower (the ancestor of the tabernacle) made of sandstone in the Flamboyant style which dates from about 1450. On the main altar, there is a marble tabernacle given by the Carthusian monastery of Pavia in 1576.