Built on the ruins of the Roman temple to Aesculapius, the Graeco-Roman god of medicine, the Isola Tiberina's 10th-century church is an interesting hybrid of architectural styles. The facade and the richly frescoed ceiling are baroque; the bell tower is 12th-century Romanesque; and the 28 columns that divide the interior date to ancient times.

Inside, a marble wellhead is thought to stand over the spring that provided the temple’s healing waters.