A fresco was found representing S. Petronilla receiving Veneranda. Several inscriptions have been found; also the columns which supported the baldachino, on which are represented the martyrdoms of SS. Achilleus and Nereus. The Romans built an altar at the springs of the river Numicius to Anna, the sister of Dido, who became the wife of the god of the river Numicius, and was called Anna Perenna. (See Ovid, "Fasti," iii. 542.) The Roman Church erected a chapel to her on the same spot, under the title of Santa Petronilla, said, without scriptural authority, to have been S. Peter's daughter, and to have died in Rome, May 30th, A.D. 98, in the reign of Domitian. This could not be the case, for Domitian died A.D. 96, and Trajan was emperor before the last of May A.D. 98, Nerva having reigned between. _Straight on leads to S. Paul's outside the walls._ _Returning to the Via Appia, on the right is the_ CHURCH OF S. SEBASTIANO, founded by Constantine, and rebuilt in 1611 from the design of Ponzio. The front and portico of six granite columns were designed by Vasanzio. Below the church are the catacombs, open free. A monk acts as guide. An altar on the right contains Bernini's statue of Sebastian, and one on the right the famous footprints. _Opposite the church_ are the extensive remains of the TOMB OF ROMULUS, SON OF MAXENTIUS. In front of the Circus of Maxentius, on the Via Appia, stands a square portico, of which only the high enclosure walls remain. These, however, are in a state of excellent preservation. _At the back of_ the modern premises, in the middle of this enclosure, are the remains of a considerable circular tomb, in front of which was a colonnade facing the Via Appia. In all probability this is the identical building erected by Maxentius in honour of his son Romulus, who died in the year 300. Representations of this tomb are to be met with on coins. _At the side is the_ CIRCUS OF MAXENTIUS, erected A.D. 310, the enclosure walls of which have been preserved almost entire. These display the interesting phenomenon of pots of earthenware built into them, which not merely expedited the progress of the work, but allowed of its being more easily repaired than was possible in any other mode of construction. Its length was 1574 feet, and breadth 269, and 18,000 spectators could be accommodated within its vast walls, yet it was a small building compared with the Circus Maximus (see page 209). In 1825 three inscriptions were found proving this to be the circus consecrated to Romulus, son of Maxentius. Two towers flank the entrance, supposed to have been the seats for the judges. It is the most perfect specimen of a Roman circus remaining. _On the top of the hill_ is the "stern round fortress of other days," known as THE TOMB OF CECILIA METELLA, [Illustration: CIRCUS OF MAXENTIUS.]