The Planetarium Science Center is celebrating the Eratosthenes Festivity, which has become an annual tradition that takes place every year on 21 June at the Bibliotheca Alexandrina and the city of Aswan. It is designed for preparatory school students, and includes a series of activities that revolve around the methodology Eratosthenes used in measuring the Earth’s circumference 2000 years ago. On 21 June, the day of summer solstice, the 21st century school students conduct Eratosthenes’ experiment at the BA Plaza and in Aswan (Upper Egypt) to measure the circumference of the earth. Moreover, other countries around the world like France, Argentina, and Spain will join the Festivity through the videoconferencing facility. The Festivity comprises a fieldtrip to Elephantine island in Aswan, interactive workshops, lectures, contests, and videoconferencing between Alexandria, Aswan and other countries to compare measurement results.