Basilica dates back to IV-V century. Its present Romanesque appearance is due to the reconstruction of the twelfth and twentieth century restorations. For over a millennium, Basilica was annexed by the most important Benedictine abbey of Vicenza. The twelfth-century main facade is in brick, flanking the two sides tombstones documenting the interventions of 1425 and 1674. Above the portal a large oculus recalls similar examples from Verona, Lombardy and Po Valley of the eleventh century. Semicircular apse of the nave is one of the most interesting components, because it documents the different periods of construction. The interior has three naves, divided by nine arches supported by columns and pillars, it has great appeal. Decoration is almost absent were some side altars and the remains of mosaic at the center, which belongs to the early church (fourth century) and represents one of the most remarkable aspects of Basilica. Crypt can be dated with certainty to the second half of the twelfth century. On the north side stands the distinctive bell tower, the best preserved part of Basilica complex, the only free from Baroque renovations. Next to is Mmartyrion, precious chapel built in the fifth century to venerate holy martyrs and to host the relics.