The ancient name for Heliopolis (city of the sun), a major city of ancient Egypt. It is first mentioned in Genesis 41 and 46 in reference to the wife of Joseph son of Jacob—she was the daughter of Poti-pherah, priest of On (not to be confused with Potiphar, captain of the guard). On’s name has been recorded in Egyptian records as I͗wnw (the pronunciation of which is unclear), translated as “The Pillars.” It was translated to On in the Hebrew. It is also referred to as Aven in Ezekiel 30:17 and Amos 1:5. It is located in present-day Ayn Shams, a northeastern suburb of Cairo.