Ath'os, MOUNT (called by modern Greeks, Holy Mountain), a mountain of Turkey, 6350 feet high, terminating the most eastern of the three peninsulas known as Chalcidice, jutting into the Archipelago. In a broader sense the whole peninsula is called Athos. The Persian fleet under Mardonius was wrecked here in 493 B. C., and to avoid a similar calamity during his invasion, Xerxes caused a canal, of which traces may yet be seen, to be cut through the isthmus that joins the peninsula to the mainland. On the peninsula there are situated about twenty monasteries and a multitude of hermitages, which contain from 6000 to 8000 monks and hermits of the order of Saint Basil. Athos was the center of Greek learning and theology, and the libraries of the monasteries are rich in literary treasures and manuscripts. The revenue of the community is derived from pilgrims and from a considerable trade in amulets, rosaries, crucifixes, images and wooden furniture.