We have seen that the metals, owing to the brilliance inherent in them, belonged in the ideas of the Iranians to the good spirits. And as the splendour of gold and silver belonged to the highest gods, so must the colours of the other turrets have been assigned to the good spirits, to whose protection each separate wall was entrusted.[502] The account which Polybius gives of the structure of the palace, the cedar and cypress wood of which the door-posts, pillars, roofs, and panels in the walls were made, shows that wood was employed in building in Media, which agrees with the habits of mountaineers. In Teheran and Ispahan buildings of wood of this kind are still in use, and no doubt the mountain forests of northern Media provided better materials in ancient times than now. The noblest trunks and best kinds of wood were sought out for the royal house. The kings of Asshur, and Nebuchadnezzar tell us in their inscriptions that they have caused trees to be cut down on this or that mountain for their buildings. The wooden palace, which Deioces, and perhaps Phraortes, first erected, must have been extended by Cyaxares, and may have been furnished by him or his successor with the brilliant ornamentation. The inner walls of the palace of the Achæmenids at Persepolis, if we may draw this conclusion from the metal supports which are found in the remains of the stone walls, were decorated in a similar manner. When the palace of the Median kings at Ecbatana had become the summer residence and treasure-house of the Persian monarchs, it would, no doubt, be enriched and adorned yet more. The temple of Anahita, connected with the palace, which Polybius has described above, is the work of Artaxerxes II. Alexander caused the spoil he had taken in Babylon, Susa, Persepolis, and Pasargadæ, to be brought to Ecbatana, where he is said to have collected 180,000 talents in gold and silver.[503] At a later time, the Arsacids are said to have resided at Ecbatana during the summer like the Achæmenids.[504] At the present day, Hamadan, which is built high up on a slope of Elvend, marks the site of the ancient Ecbatana. It contains about 40,000 inhabitants; the ruins of the ancient city have not yet been satisfactorily explored. The slender pillars with lotus-like capitals, discovered here, are like the pillars of Persepolis, and therefore might be the work of the Achæmenids; what has been discovered in engraved stones and coins comes from the time of the Arsacids and Sassanids. Some cylinders covered with cuneiform inscriptions have not yet been examined.