For the purposes of historical geography Northern Greece may be considered as divided into two parts by the great range of Pindus, which starting far up in the Macedonian mountains ends in the Parnassus group on the Corinthian Gulf. To the west in Epirus and Aetolia the whole country is a confused mass of rugged mountains with here and there a lake in a small plain as at Yánnina, and below Thermos (Kephalóvriso, Κεφαλόβρυσο). The principal rivers such as the Achelous (Aspropótamo, ʾΑσπροπόταμο) and the Arachthus (the river of Arta) run through narrow gorges except near their mouths. The main route from north to south seems to have come down Central Epirus to Ambracia (Arta, Αρτα), and thence to have crept round the coast past Amphilochian Argos into the lower Achelous valley.

To the east the formation of the country is entirely different. Great, parallel ranges starting at right-angles from Pindus run eastward to the sea and divide the land into a series of plains, in which the prehistoric settlements are found. The northernmost range, which separating the basins of the Haliacmon (Vístritsa, Injé-qára-su) and of the Peneus (Salambriás, ∑αλαμβριάς) forms the boundary between Thessaly and Macedonia, ends in Olympus. At its extreme east is the pass of Tempe which, despite its fame, never seems to have been of much practical use.