Aswan, a city on the Nile River, has been southern Egypt’s strategic and commercial gateway since antiquity. It contains significant archaeological sites like the Philae temple complex, on Agilkia Island near the landmark Aswan Dam. Philae’s ruins include the columned Temple of Isis, dating to the 4th century B.C. Downriver, Elephantine Island holds the Temple of Khnum, from the Third Dynasty
Aswan city located on the east bank of the Nile to 899 kilometers south of Cairo, a link between Egypt and Sudan and thus it is the gateway to the heart of the African continent, making it an important commercial center.
Aswan was known Bsien in Pharaonic and Hellenistic eras. And where the Eratosthenes refute the theory of flat ground and made his first account of the Earth's circumference taking Seine center and Alexandria terminal point for calculating the length of the arc between the two points and the angle of sunlight fall on each of the two cities, including by the Earth's circumference. Eratosthenes relied on the sun passes over the Tropic of Cancer (almost passing Aswan) on June 21.