|Baalbek or Heliopolis
(Ἡλιούπολις, "sun city"): town in the northern Bekaa valley,
site of the largest sanctuary in the Roman world.
Ras al-AinAt some eight hundred meters southeast from the temples of Jupiter, Bacchus, Venus, and the Muses,
is the spring called Ras al-Ain ("head of the source"). The town owes its name to this place: Ba'al Nebeq or Baalbek means "Lord of the sources".
Near the shallow pool once stood a
nymphaeum, a temple, and a small building with columns. The water of
this source was used in the above-mentioned temples, and also refreshed
the town of Baalbek. Today, there's a mosque.
A satellite photo is here.