It is most famous in antiquity as the site of the Pharos, the great lighthouse, considered one of the seven wonders of the ancient world, for the Temple of Serapis, the Serapion, which was part of the legendary library at Alexandria, as a seat of learning and, once, the largest and most prosperous city in the world. Alexandria is a port city located on the Mediterranean Sea in northern Egypt founded in 331 BCE by Alexander the Great.