This ornate Romanesque church at the colorful heart of Trastevere was founded around a.d. 350 and is one of the oldest in Rome. But parts of it were added around 1100, and more in the early 1700s. The restored mosaics on the apse date from around 1140, and below them are the 1293 mosaic scenes depicting the “Life of the Virgin Mary” by Pietro Cavallini. The faded mosaics on the facade are from the 12th or 13th century, and the octagonal fountain in the piazza is an ancient Roman original that was restored and added to in the 17th century by Carlo Fontana.