The church of San Bartholomew ("De Insula") was built by emperor Otto III during the tenth century, on the ruins of the Temple of Asclepius and was dedicated to St Adalbert. It was restored by Pope Paschal II in 1113, and then again in 1180, after being entitled to St Bartholomew. Ruined and almost destroyed by a flood of the Tiber in 1557, it was readapted and remodeled by Orazio Torriani in 1624, with a baroque façade on two floors and a portico. It was finally restored in 1852. The Romanesque bell-tower with three-mullioned windows dating back to the 12th century stands out and is visible from the banks of the Tiber. The interior of the church is divided into three naves by to two orders of fourteen antique columns. The originality of the church is to have a raised transept and apse. The panelled ceiling is rich of paintings and frescoes (1865).