This is one of the most imposing ruins in Rome; the three noble arches which formed the northern side being almost perfect, rising to the height of 95 feet, and having a span of 80 feet. The southern side was similar; whilst a noble vaulted roof, supported from the side piers and arches, covered the centre. Thus, entering from the Vicus Eros, on the east, the spectator saw a magnificent hall 333 feet long by 84 feet wide, with aisles 60 feet in width. To the central hall the tribunal at the west end was added in the rebuilding of Constantine, when he made the main entry from the Sacra Via, the ruins of which exist in the porphyry columns. By this entry the nave is 227 feet long, the tribunal being 24 feet deep, and the aisles 80 feet wide. Nibby has the merit of having been the first to prove that these ruins are the last remains of the Basilica erected by Maxentius, and completed and partially rebuilt by Constantine the Great. In 1828 a medal of Maxentius was found amongst the ruins of a piece of the vault which fell down. The principal entrance was originally intended to have been on the side facing the Colosseum, towards a street that ran out from the left of the Via Sacra, which, turning to the right, reached the Colosseum. At a later period it may have been found more suitable to add a splendid portal on the side facing the Via Sacra; opposite to which, in the central side arch, a tribune was erected. So whichever way you enter it, it is a nave with two aisles. Of the vast vaulted arches spanning the middle space, only the supports from which the arches sprang still exist. These, however, suffice to indicate what they must have been. The Basilica contained many works of art, and the roof was supported by eight columns. The Via Sacra here passed along the front of the present Church of S. Francis of the Romans, and the Arch of Titus, to the Palatine. _By applying at No. 61 Via del Colosseo, at the back of the Basilica, permission will be given to ascend to the top, from which a magnificent view is obtained._ _On our right is the_ CHURCH OF S. FRANCISCA ROMANA. Built in the ninth century, and called S. Maria Nuova. The mosaic on the apse dates from 862. There is a monument to Gregory XI., and a relief representing the return of the Papal court to Rome from Avignon. In the transept are the two stones marked with depressions, said to have been where Peter knelt when he prayed that Simon Magus might fall. (See picture in S. Peter's, page 115.) The church contains a beautiful marble _ciborium_, and monuments to Cardinal Vulcani, 1322, and General Rido, 1475. _In the Via S. Teodoro is the entrance to_ THE PALATINE HILL AND THE PALACE OF THE CÆSARS.