Heliopolis was a major city of ancient Egypt. It was the capital of the 13th or Heliopolite Nome of Lower Egypt and a major religious centre. It is now located in Ayn Shams, a northeastern suburb of Cairo.
Heliopolis was one of the oldest cities of ancient Egypt, occupied since the Predynastic Period. It greatly expanded under the Old and Middle Kingdoms but is today mostly destroyed, its temples and other buildings having been scavenged for the construction of medieval Cairo. Most information about the ancient city comes from surviving records.
The major surviving remnant of Heliopolis is the obelisk of the Temple of Ra-Atum erected by Senusret I of Dynasty XII. It still stands in its original position, now within Al-Masalla in Al-Matariyyah, Cairo. The 21 m high red granite obelisk weighs 120 tons and is believed to be the oldest surviving obelisk in the world.