Of this monument we have a description by Strabo, and ruins which substantiate the description in its main lines. It was composed of a circular basement of white marble, two hundred and twenty-five feet in diameter, which supported a cone of earth, planted with cypresses and evergreens. On the top of the mound the bronze statue of the emperor towered above the trees. This type of sepulchral structure dates almost from prehistoric times, and was in great favor with the Etruscans. The territories of Vulci, near the Ponte dell' Abbadia, and of Veii, near the Vaccareccia, are dotted with these mounds, which the peasantry call _cocumelle_. Augustus made the type popular among the Romans, as is proved by the large number of tumuli which date from his age, on the Via Salaria, the Via Labicana, and the Via Appia. His tomb was entered from the south, the entrance being flanked by monuments of great interest, such as the obelisks now in the Piazza del Quirinale and the Piazza di S. Maria Maggiore; the copies of the decrees of the Senate in honor of the personages buried within; and, above all, the _Res gestæ divi Augusti_, a sort of political will, autobiography, and apology, the importance of which surpasses that of any other document relating to the history of the Roman Empire. This was written by Augustus towards the end of his life. He ordered his executors to have it engraved on bronze pillars on each side of the entrance to his mausoleum. That his will was duly executed by Livia, Tiberius, Drusus, and Germanicus, his heirs and trustees, is proved by the frequent allusions to the document made by Suetonius and Velleius, and also by the copies which have come down to us, not from Rome or Italy, but from the remote provinces of Galatia and Pisidia. It was customary in ancient times to raise temples in honor of the rulers of the empire, and to ornament them with their images and eulogies. These were called _Augustea_ or _ædes Augusti et Romæ_ in the western provinces, σεβαστεῐα in eastern or Greek-speaking countries,[95] Ancyra (Angora), the capital of Galatia, and Apollonia, the capital of Pisidia, were the foremost among the Asiatic cities to pay this honor to the founder of the empire.