The Gulf of Argostoli is a gulf of the Ionian Sea on the island of Cephalonia, western Greece. It separates the Paliki peninsula from mainland Cephalonia, and opens toward the Ionian Sea in the south. The gulf is 13 km (8.1 mi) long and 2 to 3 km wide. Lixouri, the second-largest town of Cephalonia, is situated on its western shore, and the capital Argostoli is situated on a bay in the eastern shore. The shores of the gulf are mountainous, especially in the east.