Sinai (usu. Si'nay; properly See'ni), the sacred mountain on which Moses received the tables of the Ten Commandments, is an individual peak in a vast rocky mass that almost fills the peninsula of Sinai. This stern, treeless peninsula is situated on the north-west of Arabia, between the Gulfs of Suez and Akaba, and shut in on the north by the desert. In this mountain-mass there are three separate mountains clearly distinguishable - Mount Serbal (6750 feet); Jebel Katherin or Mount St Catherine (8540 feet), lying south-east of Serbal; and Umm Shomer (some 8000 feet). Jebel Katherin has two well-marked peaks, a northern one called Horeb and a southern called Jebel Musa (Mountain of Moses) - the latter pointed out by tradition as the scene of the Hebrew law-giving. At its foot, in a ravine, stands the fortress-like monastery of St Catherine (founded probably about 527 by the Emperor Justinian). The Sinaitic peninsula and a strip of the Red Sea shore beyond Akaba belong politioally to Egypt. See works by Hull (1885), Palmer (1871), Stanley (1856), and Haynes (1894).