The western part of this region contains the massive limestone formations so characteristic of northern and western Greece, while to the east the peninsula of Attiikí (Attica) represents the western margin of the Hercynian crystalline rocks of the Aegean shores. Essentially an upland area, its relief is articulated by four northwest–southeast-trending spurs thrusting out from the main Píndos mass. A number of distinctive basins and plains lie amid these upland ribs. The northernmost, a rather broken spur called the Kamvoúnia Mountains, runs along the coast of the Gulf of Thermaïkós and continues south to form the peninsula bounding one side of Vólou Bay. Among its peaks are Mount Ólympos (Olympus)—the mythical seat of the gods, whose often cloud-topped summit rises to 9,570 feet (2,917 metres), the highest point in Greece—and the equally fine peaks of Mounts Kisszavos (Ossa) and Pílios (Pelion). The next spur to the west is the Óthris mountain range, which continues across the narrow Oreón Channel in the northern sector of the long, narrow island of Évvoia (Euboea). Between the two spurs lie the ancient basins (formerly the site of lakes) of Thessalía (Thessaly), Tríkala, and Lárisa, drained by the Pineiós (Piniós) River. Just to the south the basin of Almyrós (Almirós), of similar origin, lies around Vólou Bay.

To the southwest the third spur leaving the Píndos is that of the Oíti, which continues in the Óchi (Ókhi) Mountains of southern Évvoia. Just before the Oíti reaches the sea, near the head of the Gulf of Maliakós, is the pass of Thermopýles (Thermopylae, scene of the famous battle of antiquity). The last (and perhaps the most important) of the four spurs thrusting down into eastern Greece is the one that curves away to the southeast through the twin-peaked mass of Mount Parnassós (Parnassus). This mountain, rising to an elevation of 8,061 feet (2,457 metres), was held to be the home of the Muses. The view from its summit at sunrise, with a broad expanse of the heart of Greece gradually unfolding, is regarded as one of the finest in the world. The range continues as the backbone of the peninsula lying between the Gulf of Évvoia and the Gulf of Korinthiakós (Corinth), and it reaches as far as Mount Párnis, just to the north of Athens. To its north lie the plains of Fokída (Phocis) and Voiotía (Boeotia), and around its southern tip lie the hotter and more arid depressions of Attiikí.

Southern Greece: the Pelopónnisos

The entire southern portion of mainland Greece forms a peninsula lying to the south of the Gulf of Korinthiakós. Technically, this region, the Pelopónnisos, also known as the Morea, is now an island, for the 3.9-mile (6.3-km) Korinthiakós Canal cuts across the narrow neck of land that formerly separated the Gulf of Korinthiakós from that of Aígina (Aíyina). The Pelopónnisos consists of an oval-shaped mountain mass with peaks rising to 7,800 feet (2,400 metres) and four peninsular prongs, which point southward toward the island of Crete (Modern Greek: Kríti). At its heart are the arid limestone plateaus of Arkadía (Arcadia), where streams disappear underground into the soluble rock and from which the barren upland of the Táygetos (Taïyetos) Mountains, reaching an elevation of 7,800 feet, extends southward to form the backbone of one of the southern peninsulas. A thin fringe of fertile coastal plain in the north and west, together with the larger alluvial depressions forming the Gulfs of Lakonia (Laconia), Messenía (Kalamata), and Argolikós (Árgolis), surrounds this mountainous core. The coast is indented and has some harbours.

Western Greece: Ípeiros and Akarnanía

Western Greece consists of Ípeiros (Epirus) and Akarnanía (Acarnania), which is the area north of the Gulf of Korinthiakós to the Albanian frontier, and is often considered to include the offshore Iónia (Ionian) Islands. The distinctiveness of western Greece is enhanced by the fact that the barrier effect of the Píndos and the ameliorating climatic influences from the west result in a quite different landscape from that of the rest of Greece. The west’s physical attributes have exaggerated its historical isolation from the other areas of mainland Greece. Fertile basins are not well developed, constricted as they are by the parallel ranges of the coastal mountains. The mountain regions themselves, however, are adequately supplied with precipitation. The flat, alluvial plain of Árta, built up from detritus brought down by the Árachthos (Árakhthos) River has become, with irrigation, a fertile agricultural region.