Heliopolis, meaning "City of the Sun," was an ancient city in Egypt, located near modern-day Cairo. It was a significant religious center dedicated to the worship of the sun god Ra. The city was known for its grand temples and obelisks, which were symbols of the sun's power and light. In addition to its religious importance, Heliopolis was a center for learning and scholarship in ancient Egypt. It housed a famous university where priests studied astronomy, mathematics, and philosophy. The city played a crucial role in the development of Egyptian culture and religion before its decline in later periods.