Heliopolis, ‘city of the sun’, in N. Egypt, with a huge temple and several obelisks. Joseph married the daughter of the high priest of On (Gen. 41: 45). In the LXX it is named as one of the cities built by the Israelites (Exod. 1: 11). The book of Jer. (43: 13) predicts that Nebuchadnezzar will break the obelisks of Heliopolis, and Ezekiel foretells that its young men will be slain (30: 17).