from Cape Gjuhëz of the Ceraunian Mountains in the north-west, to Mount Qelqëz in the north-east, to Mount Gavrovo in the south-east, to the mouth of the Ambracian Gulf in the south-west. The northern boundary of ancient Epirus is alternatively given as the Vjosa (or Aoös) river. Epirus's eastern boundary is defined by the Pindus Mountains, that form the spine of mainland Greece and separate Epirus from Macedonia and Thessaly. To the west, Epirus faces the Ionian Sea. The island of Corfu is situated off the Epirote coast but is not regarded as part of Epirus. The definition of Epirus has changed over time, such that modern administrative boundaries do not correspond to the boundaries of ancient Epirus. The region of Epirus in Greece only comprises a fraction of classical Epirus and does not include its easternmost portions, which lie in Thessaly. In Albania, where the concept of Epirus is never used in an official context, the counties of Gjirokastër, Vlorë, and Berat extend well beyond the northern and northeastern boundaries of classical Epirus. Geography and ecology Epirus is a predominantly rugged and mountainous region. It is largely made up of the Pindus Mountains, a series of parallel limestone ridges that are a continuation of the Dinaric Alps. The Pindus mountains form the spine of mainland Greece and separate Epirus from Macedonia and Thessaly to the east. The ridges of the Pindus are parallel to the sea and generally so steep that the valleys between them are mostly suitable for pasture rather than large-scale agriculture. Altitude increases as one moves east, away from the coast, reaching a maximum of 2,637 m at Mount Smolikas, the highest point in Epirus. Other important ranges include Tymfi (2,496 m at Mount Gamila), Lygkos (2,249 m), to the west and east of Smolikas respectively, Gramos (2,523 m) in the northeast, Tzoumerka (2,356 m) in the southeast, Tomaros (1,976 m) in the southwest, Mitsikeli near Ioannina (1,810 m), Mourgana (1,806 m) and Nemercke/Aeoropos (2,485 m) on the border between Greece and Albania, and the Ceraunian Mountains (2,000 m) near Himara in Albania. Most of Epirus lies on the windward side of the Pindus, and the prevailing winds from the Ionian Sea make the region the rainiest in mainland Greece. Significant lowlands are to be found only near the coast, in the southwest near Arta and Preveza, in the Acheron plain between Paramythia and Fanari, between