Baalbeck lithograph taken from page 10 of "Visit to Alexandria, Damascus, and Jerusalem; during the successful campaign of Ibrahim Pasha" by Edward Hogg, 1835. Baalbeck is a town in the Beqaa Valley of Lebanon situated east of the Litani River. After Alexander the Great conquered the Near East in 334 BC, the existing settlement was named Heliopolis. The city retained its religious function during Greco-Roman times, when the sanctuary of the Heliopolitan Jupiter-Baal was a pilgrimage site, and one of the largest sanctuaries in the empire. Starting in the last quarter of the 1st century BC (reign of Augustus) and over a period of two centuries (reign of Philip the Arab), the Romans had built a temple complex in Baalbeck consisting of three temples: Jupiter, Bacchus and Venus. On a nearby hill, they built a fourth temple dedicated to Mercury.