SIWAH is the modern name of the oasis in the Sahara, which was called by the Greeks and Romans Ammonium, Ammonia, or Ammoniaca, from the celebrated oracle and temple of Jupiter Ammon, with whose worship the Greeks became acquainted through the Cyrenteant The town of Siwah is iu 29° 12' N. lat., 26° 17' E. long., and is about 160 English miles from the sea-coast. The whole oasis is about 15 geographical miles long and 12 miles broad, but Diodorus (xvii. 50) says that the length and breadth are about 50 stadia, which would only make a little more than 5 geographical miles. The surface is undulating, and in the north it is surrounded by high limestone hills; it is watered by many springs of fresh as well as of salt-water, the latter of which probably arise from the masses of salt mentioned by Herodotus. Tho ancients speak of three things as remarkable in this oasis : first, a well, called the Well of the Suu, of which the water was warm iu the morning and evening, and cold at mid-day (Herod., iv. 181; Diodor., xvii. 50; Lucr., vi. 849, &c. ; I'omp. Mela, i. 8); secondly, a large palace of the ancient kiuga of the Ammouians, which was surrounded by a triple wall, and situated in the centre of the oasis (Diodor., xvii. 50); and thirdly, the temple of Jupiter Ammon, which was surrounded by a shady grove. Cambysea made an unsuccessful attempt to take the Ammouium (Herod., iii. 25); and it was visited by Alexander the Great In the reign of the Ptolemies and under the Romans the oasis belonged to that nomos or province which was called Libya (Ptolem., iv. 5). In the time of Strabo (xvii, p. 813) the oracle was almost entirely neglected. In the middle ages the Arabs called this oasis Santariab.
The Ammonium, during its most flourishing state in ancient times, seems to have been well peopled; and the inhabitants, who lived in villages, are said to have consisted of three distinct tribes. The southern and western parts were inhabited by /Ethiopians, the middle part by the Nasamonea, and the north by a nomadic tribe of Libyans. The description which Diodorue gives of the beautiful climate of the oasis, and of its fertility, especially in fruit, is still applicable to it ; nearly the whole oasis forms an uninterrupted succession of meadows, fields, and palm-groves; and the gardens produce an abundance of the moat delicious fruits. The water however is said to be injurious to camels.
The present iuhabitanta consist chiefly of Berbers mixed with negroes, and all are very zealous Mohammedans. The principal place in it bears the name of Siwah, and has about 8000 inhabitants. This town and several other smaller places in the oasis are built upon eminences, and surrounded by walls to protect them from hostile inroads. The houses are all wretched huts, and the streets are narrow and dark.
Itulus of the ancient temple of Ammon are still visible. The paintings, sculptures, and hieroglyphics which remain on the walls, are copied and described in the work of MinutolL There are also ruins of other places, especially in the neighbourhood of the modern village of Shargiab, which probably mark the sites of the ancient villages. The Well of the Sun is near Shargiah, and is still remarkable for its varying temperature. Catacombs cut in the rocks have been discovered in fonrdifferent parts of the oasis.