This Phoenician city, where a triad of deities was worshipped, was known as Heliopolis during the Hellenistic period. It retained its religious function during Roman times, when the sanctuary of the Heliopolitan Jupiter attracted thousands of pilgrims. Baalbek, with its colossal structures, is one of the finest examples of Imperial Roman architecture at its apogee.
The complex of temples at Baalbek is located at the foot of the south-west slope of Anti-Lebanon, bordering the fertile plain of the Bekaa at an altitude of 1150 m. The city of Baalbek reached its apogee during Roman times. Its colossal constructions built over a period of more than two centuries, make it one of the most famous sanctuaries of the Roman world and a model of Imperial Roman architecture. Pilgrims thronged to the sanctuary to venerate the three deities, known under the name of the Romanized Triad of Heliopolis, an essentially Phoenician cult (Jupiter, Venus and Mercury).
The importance of this amalgam of ruins of the Greco-Roman period with even more ancient vestiges of Phoenician tradition, are based on its outstanding artistic and architectural value. The acropolis of Baalbek comprises several temples. The Roman construction was built on top of earlier ruins which were formed into a raised plaza, formed of twenty-four monoliths, the largest weighing over 800 tons.
The Temple of Jupiter, principal temple of the Baalbek triad, was remarkable for its 20 m high columns that surrounded the cella, and the gigantic stones of its terrace. The adjacent temple dedicated to Bacchus is exceptional; it is richly and abundantly decorated and of impressive dimensions with its monumental gate sculpted with Bacchic figures. The Round Temple or Temple of Venus differs in its originality of layout as well as its refinement and harmonious forms, in a city where other sanctuaries are marked by monumental structures. The only remaining vestige of the Temple of Mercury located on Cheikh Abdallah Hill, is a stairway carved from the rock. The Odeon, located south of the acropolis in a place known as Boustan el Khan, is also part of the Baalbek site, and considered among the most spectacular archaeological sites of the Near East.
Baalbek became one of the most celebrated sanctuaries of the ancient world, progressively overlaid with colossal constructions, which were built during more than two centuries. Its monumental ensemble is one of the most impressive testimonies of the Roman architecture of the imperial period.