Aswan is the capital of the Aswan Governorate of Egypt, which is the southern gateway to Egypt and is located on the eastern bank of the Nile at the first waterfall of the Nile.
Its coordinates are 24.05 st. 32.56 BC. It has a population of 200,000 people. Aswan is one of the driest inhabited places on earth.
For example, there was no rain in the six years between 1995 and 2001, so it is not unusual for some rooms of Nubian village houses not to be roofed.
Aswan was known as Sien in the Pharaonic and Greek periods.
In it, Eratosthenes refuted the flat Earth theory and made the first calculation of the circumference of the Earth,
taking Sine as a center and Alexandria as a terminal point to calculate the length of the arc between
the two points and the angle of sunlight falling on each of the two cities among the Arabic cities, including according to the circumference of the Earth.
Eratosthenes relied on the perpendicularity of the sun tropic of Cancer (almost passing through Aswan) on June 21.