The pillars, beams, and the rest of the woodwork were likewise coated with thin laminse of the precious metals, even gold being used for this purpose to a certain extent.
Such seems to have been the character of the true ancient Median palace, which served probably as a model to Darius and Xerxes when they designed their great palatial edifices at the more southern capitals.

In the additions which the palace received under the Achaemenian kings, stone pillars may have been introduced; and hence probably the broken shafts and bases, so nearly resembling the Persepolitan, one of which Sir E.
Ker Porter saw in the immediate neighborhood of Hamadan on his visit to that place in 1818.

[PLATE I., Fig.

1.] But to judge from the description of Polybius, an older and ruder style of architecture prevailed in the main building, which depended for its effect not on the beauty of architectural forms, but on the richness and costliness of the material.

A pillar architecture, so far as appears, began in this part of Asia with the Medes, who, however, were content to use the more readily obtained and more easily worked material of wood; while the Persians afterwards conceived the idea of substituting for these inartificial props the slender and elegant stone shafts which formed the glory of their grand edifices.
At a short distance from the palace was the "Acra," or citadel, an artificial structure, if we may believe Polybius, and a place of very remarkable strength.