The greatest plans for the building of Rome were conceived by Julius Caesar and Nero. Of Nero's buildings nothing remains except some ruins of his Golden House beneath the baths of Titus, while the designs of Caesar were destined to be carried out by his great successor Augustus. Justly could this emperor boast that he found Rome a city of brick and left it a city of marble. The republican period succeeding the expulsion of the Tarquins, and which his accession brought to a close, had not been so fruitful in public buildings as the epoch immediately following. Of the former, the Tabularium, the tombs of Bibulus and Cecilia Metella, the temple of Fortuna Virilis, and the ruins of the Fabrician bridge, the modern Ponte Quattro Capi, have come down to us. The city, however, was beginning to assume a more majestic appearance. On the accession of Augustus, the Capitol was crowned by the Tarquins' temple to Jupiter, which was to be restored by Domitian. The valley between the Palatine and the Aventine was occupied by the enormous Circus Maximus, built by Tarquinius Priscus and decorated by Julius Caesar, and which has so entirely disappeared that we can only trace its site along the present Via dei Cerchi. The temples of Concord and Castor and Pollux stood upon the Forum Romanum, while the temple of Saturn bounding the steep _Clivus Capitolinus_ which led upwards to the Capitol--the ancient _Mons Saturninus_--recorded the golden age when Saturn reigned in Italy. The streets of the city were paved, and beyond the walls the immense Appian causeway crossed the Pontine marshes and stretched onwards towards Brindisi and the east. In the forty years following Rome was transformed. There arose in the Campus Martius, the Pantheon with the baths and aqueduct of Agrippa, the portico of Octavia dedicated by Augustus to his sister, the theatre of Marcellus and the great mausoleum where the emperor and his kindred were to lie, and which, almost smothered in poor houses, has in modern times served the ignoble offices of a bull-ring and a third-rate theatre. Temples were restored, the Basilica Julia was completed, another Forum built with the temple of Mars Ultor in its midst. Upon the site of Augustus' birthplace on the Palatine hill a great palace was raised by himself and Tiberius, and this district of Rome became henceforth the abode of the Caesars. [Illustration: THE COLOSSEUM ON A SPRING DAY The Flavian amphitheatre, called Colosseum from the _colossus_ or colossal statue of Nero which stood on the _velia_ before it. The picture is taken from an _orto_ belonging to the Barberini on the Palatine, looking across the Arch of Constantine. See pages 22, 23, 31.] Augustus and his immediate successors were to witness the golden age of Roman building. After Hadrian came the period of decadence characterised by florid ornamentation, bad taste and workmanship, which culminated under Constantine and his sons.