The imposing basilica dedicated to the patron saints of the town outstands in the central square of Trasacco. Its gabled façade is flanked by the bell tower, noticeable for its structure: it is a frustum of pyramid surmounted by a quadrangular belfry adorned with sculptures and with a carved stone block representing a fantastic animal. On the right side of the building there is the so called Men's portal, considered one of the most noteworthy masterpieces of Romanic-Renaissance architecture. It is a splayed portal framed by twisting columns and carved pillars and enriched with elegant sculptures on the capitals. The wooden portal is richly carved and engraved as well as the stone arches surmounting it. Originally the main entrance was the so called Women's Portal, which the addition of the Oratory and of a vaulted porch turned into a secondary door. It dates back to the thirteenth century and is remarkable for the decoration covering the jambs and the architrave. The interior of the church preserves frescoes dated from the fifteenth to the seventeenth century and noticeable stone sculptures of Romanic and Gothic age, like the Baptismal font and Saint Catherine's Monument. The high altar, situated in the apse, is a sarcophagus adorned with carved symbolic animals and probably belongs to the primary church. Nevertheless the most precious item is undoubtedly the pulpit, dated to the mid XIII century and decorated with engravings of the evangelists' symbol and of the Lamb. At the bottom of the left aisle there is San Cesidio's chapel, where a wooden statue of the saint is set over a gilded altar. The fourth aisle, added later to the original tripartite structure, contains four altars of remarkable artistic value.