Basilica of San Crisogono

This basilica in Trastevere rises above one of the best-preserved early Christian buildings in Rome, an underground fourth-century church discovered beneath its floor. The present church was rebuilt in the twelfth century and given a Baroque overlay in the seventeenth, when it received a coffered ceiling and a mosaic attributed to the school of Cavallini. Ancient granite columns divide the nave, and the excavated lower level, reached by a stair near the sacristy, preserves frescoes and structures spanning several centuries.