Epirus (Greek: Ήπειρος, Ípeiros), formally the Epirus Region (Περιφέρεια Ηπείρου, Periféria Ipeírou), is a geographical and administrative region in northwestern Greece. It borders the regions of West Macedonia and Thessaly to the east, West Greece to the south, the Ionian Sea and the Ionian Islands to the west and the country of Albania to the north. The region has an area of about 9,200 km (3,600 sq mi). It is part of the wider historical region of Epirus, which overlaps modern Albania and Greece but mostly lies in modern Greek territory.
Greek Epirus, like the region as a whole, is rugged and mountainous.It comprises the land of the ancient Molossians and Thesprotians and a small part of the land of the Chaonians the greater part being in Southern Albania. It is largely made up of mountainous ridges, part of the Dinaric Alps. The region's highest spot is on Mount Smolikas, at an altitude of 2.637 metres above sea level. In the east, the Pindus Mountains that form the spine of mainland Greece separate Epirus from Macedonia and Thessaly. Most of Epirus lies on the windward side of the Pindus. The winds from the Ionian Sea offer the region more rainfall than any other part of Greece.
The Vikos-Aoos and Pindus National Parks are situated in the Ioannina Prefecture of the region. Both areas have imposing landscapes of dazzling beauty as well as a wide range of fauna and flora. The climate of Epirus is mainly alpine. The vegetation is made up mainly of coniferous species. The animal life is especially rich in this area and includes, among other species, bears, wolves, foxes, deer and lynxes.
Epirus is divided into four regional units (formerly prefectures, nomoi), which are further subdivided into municipalities (dimoi). The regional units are: Thesprotia, Ioannina, Arta and Preveza.
From January 2011, according to the reform introduced by the Kallikratis Programme (Act 3852/2010) the prefectures were abolished and replaced by regional units. The former municipalities and communities were re-structured to form only 18 new municipalities.