Heliopolis or the city of sun, as the Greeks called it, is an ancient Egyptian city that was called by the Egyptians Annu. It was erected by the priests of Ra as a religious capital of Egypt that included a temple for Ra and college with a great library. The historians say that many great thinkers like Thales, Plato, and Plutarch came to this city and made use of its valuable library.
In the 5th dynasty, the priests of Ra established the temple of Ra on an artificial hill known as the high sand to the north of the town. This high sand was a symbol for the place from which Ra arose to the universe.
The interior plan of the temple involved an open court in which there was a Benben Stone that was believed to catch the sun rays every morning to highlight that Ra was in his temple. In the lower part of this Benben stone or obelisk there was a place for leaving the sacrifices for the sun god. As it is recorded, about 100,600 meals of bread, beer, and cake were sacrificed by the kings, priests and royal court for the god of sun.
The main plan of the temple was surrounded by a thick, high wall. It is registered that a large mud-brick replica was established next to this thick wall to be the place of Ra's solar sun. The old temple was renovated at the reign of Sesotris I who added two handsome granite obelisks with metal caps on their top to reflect the rays of the sun in the entrance of the temple.
Some historians say that Mary rested in that city and washed the clothes of her son Jesus in the water of the temple's fountain that was located nearby the temple. The major part of this city disappeared now but the myths around it still exist.
The religious system of Heliopolis remained from the third to the fifth dynasty. After that the mythology of Memphis appeared and the two mythologies began to merge together. Since the fifth dynasty, and after the priests of Heliopolis attempts to spread the name of their god allover Egypt, the Egyptian Kings paid a great attention to the association of themselves to the gods by making up new myths such as the ennead which is a group of nine gods.