Alexandria extends about 20 miles (32 km) along the coast of the Mediterranean sea in north-central Egypt. It is home to the Bibliotheca Alexandrina, the New Library of Alexandria, and is an important industrial centre because of its natural gas and oil pipelines from Suez. In ancient times, Alexandria was one of the most famous cities in the world. It was founded around 331 BC by Macedonian ruler Alexander the Great, and remained Egypt's capital for nearly a thousand years, until the Arabs conquered Egypt in 641 AD and set up a capital at Fustat (later absorbed into Cairo). Alexandria was known for the Lighthouse of Alexandria (one of the Seven Wonders of the Ancient World), the Library of Alexandria (the largest library in the ancient world) and the Catacombs of Kom el Shoqafa (one of the Seven Wonders of the Middle Ages). Ongoing maritime archaeology in the harbour of Alexandria (which began in 1994) is revealing details of Alexandria both before the arrival of Alexander, when a city named Rhakotis existed there, and during the Ptolemaic dynasty.