on the Pincian Hill covered with the gardens of Lucullus, to possess which Messalina caused the death of Valerius Asiaticus, into whose possession they had fallen.  In the valley which lay between the fora and the Quirinal was the celebrated Subura, the quarter of shops, markets, and artificers,—­a busy, noisy, vulgar section, not beautiful, but full of life and enterprise and wickedness.  The eye then turned to the north, and the whole length of the Via Flamina was exposed to view, extending from the Capitoline to the Flaminian gate, perfectly straight, the finest street in Rome, and parallel to the modern Corso; it was the great highway to the north of Italy.  Monuments and temples and palaces lined this celebrated street; it was spanned by the triumphal arches of Claudius and Marcus Aurelius.  To the west of it was the Campus Martius, with its innumerable objects of interest,—­the Baths of Agrippa, the Pantheon, the Thermae Alexandrinae, the Column of Marcus Aurelius, and the Mausoleum of Augustus.  Beneath the Capitoline on the west, toward the river, was the Circus Flaminius, the Portico of Octavius, the Theatre of Balbus, and the Theatre of Pompey, where forty thousand spectators were accommodated.  Stretching beyond the Thermae Alexandrinae, near the Pantheon, was the magnificent bridge which crossed the Tiber, built by Hadrian when he founded his Mausoleum, to which it led, still standing under the name of the Ponte S. Angelo.  The eye took in eight or nine bridges over the Tiber, some of wood, but generally of stone, of beautiful masonry, and crowned with statues.  In the valley between the Palatine and the Aventine, was the great Circus Maximus, founded by the early Tarquin; it was the largest open space, inclosed by walls and porticos, in the city; it seated three hundred and eighty-five thousand spectators.  How vast a city, which could spare nearly four hundred thousand of its population to see the chariot-races!  Beyond was the Aventine itself.  This also was rich in legendary monuments and in the palaces of the great, though originally a plebeian quarter.  Here dwelt Trajan before he was emperor, and Ennius the poet, and Paula the friend of Saint Jerome.  Beneath the Aventine, and a little south of the Circus Maximus, were the great Baths of Caracalla, the ruins of which, next to those of the Colosseum, made on my mind the strongest impression of all I saw that pertains to antiquity, though these were not so large as those of Diocletian.  The view south took in the Caelian Hill, the ancient residence of Tullus Hostilius.  This hill was the residence of many distinguished Romans, among whose palaces was that of Claudius Centumalus, which towered ten or twelve stories into the air.  But grander than any of these palaces was that of Plautius Lateranus, on whose site now stands the basilica of St. John Lateran,—­the gift of Constantine to the bishop of Rome,—­one of the most ancient of the Christian churches, in which, for fifteen hundred years, daily services have been performed.