In 332 B.C.E. Macedonian Greek forces under Alexander the Great managed to breach the “impregnable” walls of the Phoenician island city of Tyre (in southern Lebanon) by actually altering the local geography. Alexander ordered the building of a 200-foot-wide causeway, or mole, to link the mainland to the island. The arch is said to mark the spot where construction of the mole first got underway.