Externally they were clamped together in the same careful way which we find to have been in use both at Persepolis and Parsargadae.

The building seems to have been closed originally by two ponderous stone doors.

[PLATE LIV., Fig.
1.] [Illustration: PLATE LIV.] Another remarkable construction, which must belong to a very ancient period in the history of the country, is a gateway composed of enormous stones, which forms a portion of the ruins of Istakr.

[PLATE LIV., Fig.
2.] It has generally been regarded as one of the old gates of the city; but its position in the gorge between the town wall and the opposite mountain, and the fact that it lies directly across the road from Pasargadae into the plain of Merdasht, seem rather to imply that it was one of those fortified "gates," which we know to have been maintained by the Persians, at narrow points along their great routes, for the purpose of securing them, and stopping the advance of an enemy.

On either side were walls of vast thickness, on the one hand abutting upon the mountain, on the other probably connected with the wall of the town, while between them were three massive pillars, once, no doubt, the supports of a tower, from which the defenders of the gate would engage its assailants at a great advantage.
We have now described (so far as our data have rendered it possible) all the more important of the ancient edifices of the Persians, and may proceed to consider the next branch of the present inquiry, namely, their skill in the mimetic arts.