Located in southern Europe, Greece forms an irregular-shaped peninsula in the Mediterranean with two additional large peninsulas projecting from it: the Chalcidice and the Peloponnese. The Greek islands are generally subdivided into two groups, according to location: the Ionian islands (including Corfu, Cephalonia, and Leucas) west of the mainland and the Aegean islands (including Euboea, Samos, Chios, Lesbos, and Crete) to the east and south. North-central Greece, Epirus, and western Macedonia are all mountainous. The main chain of the Pindus Mountains extends from northwest Greece to the Peloponnese. Mount Olympus, rising to 9,570 ft (2,909 m), is the highest point in the country.