Easton's 1897 Bible Dictionary:

Baalbec
   called by the Greeks Heliopolis i.e., "the city of the sun",
   because of its famous Temple of the Sun, has by some been
   supposed to be Solomon's "house of the forest of Lebanon" (1
   Kings 7:2; 10:17; 2 Chr. 9:16); by others it is identified with
   Baal-gad (q.v.). It was a city of Coele-Syria, on the lowest
   declivity of Anti-Libanus, about 42 miles north-west of
   Damascus. It was one of the most splendid of Syrian cities,
   existing from a remote antiquity. After sustaining several
   sieges under the Moslems and others, it was finally destroyed by
   an earthquake in 1759. Its ruins are of great extent.