Hermus or Hermos (Greek, Ancient (to 1453);: Ἕρμος) was a deme of ancient Attica. It lay on the sacred road to Eleusis, between the Cephissus and the Pythium, a temple of Apollo on Mount Poecilum, upon a rivulet of the same name. Here was the splendid monument of Pythonice, the wife of Harpalus.[1] [2]
The site of Hermus is tentatively identified with Chaidari.