The facade originally had a crowning triangular pediment and was preceded by a portico. Today it is divided into two levels: on the bottom there are three elegant stone portals, and Roman-themed friezes on the lintels; at the top there are three windows. The sides are topped by a pediment with a triangular gable, while the centre has two pillars supporting a rounded arch with the ring decorated with classical motifs. Traces of plaster on the front suggest that it was covered for the entire higher order.

The interior of the basilica has a nave and two side aisles, concluding with a semicircular apse and two square apses. The aisles, with a higher central aisle, are divided by Doric columns, supporting an entablature. The presbytery, framed by a triumphal arch and delimited by Corinthian columns, is covered by a dome with eight segments resting on four tall corner columns. In the middle of the apse, in a niche, there is a frescoed monogrammed cross which, along with traces of faux marble decoration, are examples of the oldest painted decorations.
On top there is a Madonna with child and saint, a fragmentary fresco from the thirteenth century, and next to this a fifteenth century Crucifixion.