a chamber under the platform; on either side the platform is solid, after which there are two vaulted chambers. On the north side of the palace there is another group of much-ruined buildings on the lower level. The arcaded corridor (103) ends at this point in a narrow vaulted chamber (104) which lies under No. 106. Like 106, No. 104 has two arched niches in the south wall. It abuts at its western end against the ramp which descends from No. 106. A narrow passage leads out into a large enclosure, court Y, in which all the walls are ruined. Plate 63, Fig. 2, shows the eastern end of No. 106 with its vault partially preserved, and the walls and substructures of No. 24. In the south-west angle of court Y there was a large chamber (105), and the north-west corner was occupied by two groups of three rooms lying to north and south of the small court Z. Possibly there was a somewhat similar arrangement of rooms on either side of court Z[1]. CHEHÂR QAPÛ Like the palace of Khusrau, Chehâr Qapû faces east. It covers a rectangular area 134 metres from east to west, and 82·60 metres from north to south (Plate 64). The building materials are the same as those used in the larger palace. The principal entrance is in the east end; I saw nothing of the great portico which M. de Morgan places on the south side, and as the outer wall at that point is entirely ruined, it is impossible to say whether there were a door there or no. The eastern gateway is much ruined (Plate 65, Fig. 1),[47] but the transverse arch between chambers 1 and 2 is standing. To north and south lie a series of courts and small chambers, occupying a width from east to west similar to that of the gateway buildings and apparently appertaining in some way to the entrance, since they do not communicate with the interior of the palace. The eastern wall both of the gateway and of the outer courts has fallen, so that the architectural scheme of the façade cannot be determined. It is certain, however, that it was not symmetrical, for the courts are not symmetrically disposed, nor is the north wing equal in length to the south wing. To the south of the central gate lie two courts, A and B, 10·10 metres from north to south, and 9·35 metres from east to west. Court A is provided with a pair of small rectangular chambers on either side; in court B there are two rooms upon the south side only. There are slight variations in size between these chambers, but they average about 4·10 metres square. They communicated with the court, but not with one another. They have all been covered by conical domes set over the angles on squinch arches. I give an example from No. 6 which will serve to illustrate the construction in every case (Plate 65, Fig. 3). Many of the rooms had a small niche in one wall (Plate 65, Fig. 2), the ṭâqchah, which is to be seen in all Persian houses; it appears again in numerous rooms in the body of the building. In No. 6