Megara (Greek: Μέγαρα, "Big Houses") is an ancient city (pop. 23,032 in 2001) in Attica, Greece. It lies in the northern section of the Isthmus of Corinth opposite the islan of Salamis, which belonged to Megara in archaic times, before being taken by Athens. Megara was one of the four districts of Attica, embodied in the four mythic sons of King Pandion II, of whom Nisos was the ruler of Megara. Megara was also a trade port, its people using their ships and wealth as a way to gain leverage on armies of neighboring polises. It possessed two harbors, Pegae, to the west on the Corinthian Gulf and Nisaea, to the east on the Saronic Gulf of the Aegean Sea.