A titular minor basilica. It was founded at the end of the 10th century by Otto III, Holy Roman Emperor. It contains the relics of Saint Bartholomew the Apostle, and is located on Tiber Island, on the site of the former temple of Aesculapius. (There is still a hospital on the site). The church was badly damaged by a flood in 1557 and was reconstructed, with its present Baroque façade, in 1624, to designs of Orazio Torriani. In the center of the piazzetta before the church is a four-sided guglia (pyramidal shape) with saints in niches by the sculptor Ignazio Jacometti, erected here in 1869. The 12th-century tower near the church, the Torre dei Caetani, is all that remains of the medieval castello erected on the island by the Pierleoni.