The rock-tombs south-east of Mandisha, mentioned by Ascherson (_l.c._ p. 145), may possibly be further remains of the Egyptian epoch, and the same is the case with some rock-chambers found by the Survey in the south part of the oasis, some 3 kilometres south of Ain el Haiss. The latter are excavated in an isolated rock-mass (sandstone) some 20 metres in diameter and 6 metres high. The chief entrance is on the south-east side of the rock, by what looks from a short distance like a mere crack; this entrance leads into a series of four small low chambers (each about 3 metres square), with a deeper channel running along the centre. Other similar chambers are found entering from the north side. No inscriptions appear to exist except a few Arabic scratches near the principal entrance, and the chambers were empty. (_b_) ROMAN ANTIQUITIES. The Roman structures in the oasis differ generally from those of the Egyptian era in being built of crude brick instead of stone. They show, however, a great solidity of construction; for this reason these erections of the Romans have in many cases outlasted those of the Coptic period which were built long afterwards; in Baharia the old Roman underground aqueducts still serve for the conveyance of water from the springs to the irrigated tracts, and the present inhabitants are far too indolent to construct similar channels for themselves. According to Ascherson (_l.c._ p. 140) the village of El Qasr owes its name to a Roman castle, abundant remains of which still exist under the modern houses. The most important of the Roman ruins of Baharia was however until recently an arch situated close to the north of El Qasr. Cailliaud (_l.c._ p. 183) describes the structure (as seen in 1820) as consisting of an “arc de triomphe” standing on an embankment 39½ metres long, with a dressed stone revetment;[66] this embankment rises 10 metres from the ground-level at the north side, and is level with the soil of the village to the south. The principal façade is to the north. The courses of the masonry are 27 to 30 centimetres high, and show a peculiar construction, headers and stretchers being built in alternate courses. The wall, which was about 2·3 metres thick, and built with a strongly-marked batter, had an ornamental cornice all round; above this came a sort of parapet 90 centimetres high. The substance of the embankment is a kind of concrete of irregularly-shaped stones set in cement.