196 ALONG THE PERSIAN GULF COAST [Chap. VII
only 4 feet wide, is flanked by high and solid walls, the outer one forming a narrow barbican. In the flooring stone of the gate is seen a socket for the pivot of a single door.
After passing through the narrow winding gateway a small piece of flat
ground is reached which holds the main cistern of the stronghold. It measures 118 feet in length and 9 feet across, and was once covered with a barrel vaulting.
As most of this has fallen in, the present depth of the cistern is only 11 feet. The
sides are coated with a hard plaster which has remained in fair condition in this as in numerous other cisterns. The water once collected in the main cistern was
furnished by the drainage descending in the nullah which, as seen in Fig. 64, cuts across the plateau approximately from south to north and runs down towards the gate. The flow of this drainage, no longer controlled, may be held to account for the gap now found in the defences to the west of the gate.
Proceeding along the wall to the north-west, a succession of ruined cisterns is met, mostly small and retaining but little of the domed superstructure which
once covered them. Wall foundations up to 2 feet wide, found close to these
cisterns, mark the position of modest dwellings, now completely decayed, which were meant to be served by their water. Most of these cisterns are circular in
shape, with diameters varying from 5 to 13 feet, but some are oblong or square.
All of them appear to have been excavated right through the hard calcareous rock which covers the top of the plateau into the underlying clay. It was the
permeable nature of this soil which made plaster lining essential for the storage
of rain-water; and the damage this lining has suffered in the course of time explains why none of the cisterns I examined held water. Altogether thirty-six
of them were counted by us on that part of the plateau which rises to the west of the ravine above mentioned. Measurement by pacing showed the hill-top to extend about 520 yards from the precipitous edge at its western extremity to the eastern brink of the plateau, with a maximum width of some 260 yards measured along the ravine from south to north.
Along this shallow ravine and to the east of it, the remains of dwellings are found closely crowded together by the side of the tanks, and are very conspicuous ( Fig. 64) . They consist of wall foundations excavated from the rock floor, walls of small quarters coarsely built with uncut slabs of stone, and rooms of modest size cut into the stratum of cretaceous sandstone where it slopes steeply and is exposed. In numerous places natural cavities or overhanging shelves have been utilized for rough quarters. The cisterns counted to the east of the ravine brought up their total number to some seventy. Two of them of circular shape and about 10 feet in diameter still preserve their domes with remains of the covering plaster. Another higher up to the south measures 13 feet in diameter,