His choice lay between Susa and Persepolis, between Ecbatana and Babylon, according as the heat of the summer or the cold of the winter induced him to pass from the plains to the mountains, or from the latter to the plains.  During his visits to Babylon he occupied one of the old Chaldaean palaces, but at Ecbatana he possessed merely the ancient residence of the Median kings, and the seraglio built or restored by Xerxes in the fashion of the times:  at Susa and in Persia proper, the royal buildings were entirely the work of the Achaemenids, mostly that of Darius and Xerxes.  The memory of Cyrus and of the kings to whom primitive Persia owed her organisation in the obscure century preceding her career of conquest, was piously preserved in the rude buildings of Pasargadae, which was regarded as a sacred city, whither the sovereigns repaired for coronation as soon as their predecessors had expired.  But its lonely position and simple appointments no longer suited their luxurious and effeminate habits, and Darius had in consequence fixed his residence a few miles to the south of it, near to the village, which after its development became the immense royal city of Persepolis.  He there erected buildings more suited to the splendour of his court, and found the place so much to his taste during his lifetime, that he was unwilling to leave it after death.  He therefore caused his tomb to be cut in the steep limestone cliff which borders the plain about half a mile to the north-west of the town.  It is an opening in the form of a Greek cross, the upper part of which contains a bas-relief in which the king, standing in front of the altar, implores the help of Ahura-mazda poised with extended wings above him; the platform on which the king stands is supported by two rows of caryatides in low relief, whose features and dress are characteristic of Persian vassals, while other personages, in groups of three on either side, are shown in the attitude of prayer.  Below, in the transverse arms of the cross, is carved a flat portico with four columns, in the centre of which is the entrance to the funeral vault.  Within the latter, in receptacles hollowed out of the rock, Darius and eight of his family were successively laid.

Xerxes caused a tomb in every way similar to be cut for himself near that of Darius, and in the course of years others were added close by.*

     * The tomb of Darius alone bears an inscription.  Darius III.
     was also buried there by command of Alexander.

[Illustration:  260.jpg THE TOMB OF DARIUS]

     Drawn by Faucher-Gudin, from the heliogravure by Marcel
     Dieulafoy.

Both the tombs and the palace are built in that eclectic style which characterises the Achaemenian period of Iranian art.  The main features are borrowed from the architecture of those nations which were vassals or neighbours of the empire—­Babylonia, Egypt, and Greece; but these various elements have been combined and modified in such a manner as to form a rich and harmonious whole.