the church of Santa Maria Assunta stands on the site of a more ancient building, called Santa Maria de Bishopric, was built in the XII century in Norman Age, datable between 1125 (the beginning of the construction of the crypt) and 1180 (completion of the upper church). The building was consecrated only a century later, 23 May 1283. The Romanesque cathedral was in three naves divided by columns with a trussed ceiling, false women's galleries and mosaic floor. This church today remain few traces, due to the renovation of the building during the Eighteenth Century (between 1730 and 1752 under the Bishop Paul de Mercuzo), which led to the total reconstruction of the interior according to the baroque taste: belong to the ancient Romanesque church the rear prospectus, closed between two bell towers (of which the smallest however is of the Seventeenth Century), part of the area of the presbytery and the crypt.
The interior of the church has three naves divided by pillars, with ample transept, three side chapel for side and large high altar. The apse is completely covered with paintings of the painter giovinazzese Carlo Rosa del 1676, depicting Maria Assunta and other saints. In the right arm of the transept and the area of the Presbytery, in the course of the restoration works of the 1990s of the last century, were brought back to light the traces of the mosaics of the ancient Romanesque flooring of the cathedral, dating from the end of the XII century.
From the left nave you descend into the crypt, the oldest part of the cathedral. It is composed of 10 columns and 12 pillars projecting from the perimeter walls. Tombstones are present in the walls and in the floor; among these the young Antonio Sindolfi of 1386.