There was a sanctuary in a private house before this Medieval church was built. It was greatly modified from the 16th to 19th century. There is still a Byzantine-style, 9th-century mosaic inside. A statue of St. Cecilia, by Stefano Maderno (1599) stands above the altar. In the crypt, you can see the sarcophagus of St. Cecilia and her husband St. Valerian. Don't miss the superb Last Judgment by Pietro Cavallini, a Medieval Roman painting masterpiece.