Extract

Thessaly, region of northern Greece, divided into the four tetrades (districts) of *Thessaliotis, *Hestiaeotis, *Pelasgiotis, and *Phthiotis, along with the so-called perioecic regions (see perioikoi) of Perrhaebia (see perrhaebi), Magnesia, Achaea Phthiotis, and Dolopia. Comprising two vast plains divided by the modern Revenia hills, Thessaly is enclosed by mountains (notably *Olympus(1), *Ossa, *Pelion, Othrys, and Pindus) which, far from forming obstacles to communication with neighbours, are pierced by valleys and passes with the generic ancient name of tempē (cf. tempe), by which, in all periods, travellers, merchants, and armies have reached the Thessalian plains. Thessaly has access to the sea only by the gulf of *Pagasae, with its two neighbouring ports, the one in the bay of Volos, in antiquity successively Iolcus, Pagasai, and *Demetrias, and the other in the bay of Halmyrus (Pyrasus, or Demetrieum, absorbed c.