Megara is a historic town and a municipality in West Attica, Greece. It lies in the northern section of the Isthmus of Corinth opposite the island 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 poleis. Megara specialized in the exportation of wool and other animal products including livestock such as horses. It possessed two harbors, Pagae to the west on the Corinthian Gulf, and Nisaea to the east on the Saronic Gulf of the Aegean Sea.

Salamis or Salamina is the largest Greek island in the Saronic Gulf, about two kilometres from the coast of Piraeus and about 16 km west of central Athens. The chief city, Salamina, lies in the west-facing core of the crescent on Salamis Bay, which opens into the Saronic Gulf. On the eastern side of the island is its main port, Paloukia, the second largest port in Greece in terms of size, after the port of Piraeus.