Baalbek or Heliopolis (Ἡλιούπολις, "sun city"): town in the northern Bekaa valley, site of the largest sanctuary in the Roman world.
Temple of Jupiter: Propylaea
The Propylaeae (a technical expression for the access gate to an ancient sanctuary) of the temple of Jupiter in Baalbek were planned in the second quarter of the second century, but completed in the first half of the third century CE. They consist of a monumental stairs, leading to the terrace, and a portico with twelve tall columns of Egyptian granite. Three of these have bases with inscriptions that mention the emperor Caracalla.note[CIL, 3.138; EDCS-17700135.] Fifty meters wide and twelve meters deep, the portico can only have been covered by a ceiling made of cedar wood.
The original staircase, fifty meters wide, was demolished when, in the age of the Crusades, the sanctuary was converted into a fortress. The present stairs were added in 1905 by the German emperor Wilhelm II, who had ordered the first excavations after he had visited Baalbek in 1898.
To the north and south of the staircase were two towers, which may have been used by the temple guard that kept an eye on the people who, through the Propylaea, walked to the Hexagonal court. A raised threshold served as a boundary between the profane and the sacred.