Fayoom, Or Fayum (Copt. Phioum, the waters), a valley of central Egypt, anciently the Arsinoite nome, about 40 m. S. W. of Cairo, on the W. side of the Nile; length from E. to W. about 40 m., breadth about 30 m.; pop. nearly 150,000. It is of an almost oval form, enclosed by a chain of the Libyan hills, which here bend round to the west and north. It forms in fact a basin with only one opening toward the Nile on the east, and gradually sloping toward the north and south, the northern depression being occupied by the Birket-el-Keroon, long supposed to be identical with Lake Moeris. It is supplied with water from the Bahar Yusef (canal of Joseph), which is divided into numerous branches to irrigate the country. The parts thus watered are remarkably fertile, producing grain, cotton, olives, figs, apricots, and other tropical fruits. Roses are abundant, and the natives produce large quantities of rose water, which is sold all over Egypt. The principal town is Medinet el-Fayoom (anc. Crocodilopolis and Arsinoe), near which are several broken columns of red granite, carved in old Egyptian style with lotus-bud capitals, supposed to mark the site of the famous labyrinth described by Herodotus. N. of the town Belzoni found two immense stone pedestals, called by the natives Pharaoh's feet, various granite statues, some wrought iron, and a quantity of half melted glass.

At some distance stands a syenite obelisk, 43 ft. high and covered with sculptures. About 3 m. from the lake stands a temple known as Kasr Keroon, 94 ft. long, 63 ft. broad, and 40 ft. high, with 14 chambers, which appears to be of the Roman period. On the S. W. bank of the lake are what are supposed to be the remains of Bacchis. The direction of the principal streets and the ground plans of houses may still be traced.