On the right bank of the Tiber are situated two distinct quarters: towards the N. the Borgo, or quarter of the Vatican; and farther S., Trastevere. They are connected by means of the long street known as the Lungara.
Electric Tramway from the Piazza delle Terme, the Piazza Venezia, or Porta San Giovanni, see Nos. 1, 14, 6, 7, and 16 in the Appx. — Omnibus from the Piazza di Venezia or the Piazza di Spagna, see Nos. 3 and 6 in the Appendix.
The district between Monte Mario and the Janiculum was known in antiquity as the Ager Vaticanus, perhaps from a vanished Etruscan town Vaticum(?). The plain by the river, notorious for its malaria, was never reckoned as part of the city in ancient times, and was not enclosed within Aurelian's wall. It was once covered with the gardens of the emperors, and here Caligula constructed a circus and embellished it with a large obelisk. This circus was the scene of the chariot-races of Nero and of his revolting cruelties to unoffending Christians in the year 65. ('Pereuntibus addita ludibria, ut ferarum tergis contecti laniatu canum interirent, aut crucibus adfixi, aut flammandi, atque ubi defecisset dies, in usum nocturni luminis urerentur.' Tacitus, Ann. xv. 44.) On the ruins of the ancient walls thus hallowed by the first great martyrdoms at Rome rose the Church of St. Peter, in the immediate neighbourhood of which paganism maintained its footing with greater obstinacy than in any other part of the city. To the N. of the circus were situated highly-revered shrines of the Phrygian Cybele (Mater Deum Magna Idaea) and of Mithras, which flourished well into the Christian period (to the end of the 4th cent.) and were frequently referred to in later antiquity shortly as Phrygianum and Vaticanum respectively. Another circumstance which tended to shape the future of this part of the city was the erection by Hadrian of his gigantic tomb in the gardens of Domitia beside the river. This monument was afterwards converted into a têtede-pont, but at what date is uncertain (perhaps by Honorius in 405). In 537 it effectually repelled the attacks of the Ostrogoths, and since that period the Castle of Sant' Angelo (as it was afterwards called) has been the citadel of Rome, on the possession of which the mastery over the city has always depended. Around the Church of St. Peter sprang up a number of chapels, churches, monasteries, and hospitals, and in the pontificate of Symmachus (498-514) a papal residence also. Foreign pilgrims soon began to establish