"History has few stronger contrasts than when it shows us Paul preaching Christ under the walls of Nero's palace. Thenceforward there were but two religions in the Roman world; the worship of the emperor, and the worship of the Saviour. The old superstitions had long been worn out; they had lost all hold on educated minds.... Over against the altars of Nero and Poppæa, the voice of a prisoner was daily heard, and daily woke in grovelling souls the consciousness of their divine destiny. Men listened, and knew that self-sacrifice was better than ease, humiliation more exalted than pride, to suffer nobler than to reign. They felt that the only religion which satisfied the needs of man was the religion of sorrow, the religion of self-devotion, the religion of the cross."--_Conybeare and Howson._ Hence, we may ascend through some gardens beneath the Villa Mills, to the terrace which surmounts the grand ruins at the end of the Palace of the Cæsars, supposed to be remains of the _Palace of Nero_, but as no inscriptions have been discovered, no part of it can be identified.[149] These are by far the most picturesque portions of the ruins, and few compositions can be finer than those formed by the huge masses of stately brick arches, laden with a wealth of laurustinus, cytizus, and other flowering shrubs, standing out against the soft hues and delicate blue and pink shadows of the distant Campagna. Beneath the terrace is a fine range of lofty chambers, with a broken statue at the end, through which there is a striking view. One of these ruined halls has been converted into a kind of museum of architectural fragments found in this part of the palace, many of them of great beauty. This was the portion of the palace which longest remained entire, and which was inhabited by Heraclius in the seventh century. Some consider that these ruins were incorporated into the _Septizonium of Severus_, so called from its seven stories of building, erected A.D. 198, and finally destroyed by Sixtus V., who carried off its materials for the building of St Peter's. It was erected by Severus at the southern corner of the palace, in order that it might at once strike the eyes of his African compatriots,[150] on their arrival in Rome. He built two other edifices which he called Septizonium, one on the Esquiline near the baths of Titus, and the other on the Via Appia, which he intended as the burial-place of his family, and where his son Geta was actually interred.