or SIPHNO (anc. Siphnos), an island in the Ægean Sea, belonging to Greece, lying between N. Lat. 36° 50' and 37° 10'; E. Long. 25° 10'; to the S.E. of Serpho and N.E. of Milo. It is oblong in shape, and about 30 miles in circuit. A chain of mountains traverses the island from N.W. to S.E., the highest point of which, 3000 feet above the sea, is crowned with the small monastery of St Elias. On the eastern slope of these hills there is a plateau, about 1000 feet high, on which stand most of the villages of the island. Siphanto was anciently celebrated for its rich gold and silver mines; but these have long since been exhausted. The land is now chiefly laid out in vineyards, and supports a few horses, cattle, and sheep. The soil is fertile, and the climate salubrious. Many of the productions form articles of exportation from the island; such as corn, figs, honey, wax, sesame, silk, and cotton. The only considerable towns are Castro, the capital, and Stauroi, both on the east side of the hills. At the south-east extremity of the island is a harbour, called Pharos, with a lighthouse. Siphnos was colonized by Ionians from Athens; and from its valuable mines it became one of the richest islands in the Archipelago. The inhabitants fought on the side of the Greeks at Salamis; and afterwards submitted to the Athenian supremacy. They were celebrated in ancient times for the manufacture of pottery. Pop. 7000.