Grevena is one of the youngest administrative prefectures of Greece.
Legislative Decree No. 4398/30-10-1964 states "On the Establishment of Piraeus and Grevena prefectures and certain other provisions," the removal of the province of Grevena prefecture of Kozani, and the City Deskatis and Communities Dassohori and Paraskevi from the prefecture of Larissa.
The county seat is the city of Grevena.
This presidential decree defines the bounds of the law, and the establishment of prefectures.
Western Macedonia is comprised of four prefectures, Grevena, Kozani, Kastoria and Florina.
According to Law 3852/2010 (Government Gazette issue A 87/7-6-2010 ') on "New Architecture of Government and Decentralized Administration - Program Kallikratis" Grevena consists of two municipalities, Grevena and Deskati.
According to the results of the 2011 census, the population of Grevena is approximately 31,500 (Grevena municipality 25,620 and the Deskatis municipality 5870) with a population density of about 14 people per square kilometer.
Geography of Grevena Prefecture
The prefecture of Grevena lies in the southwestern part of Western Macedonia. It's northeast border is with the Kozani prefecture and lies to the east of the prefectures of Kozani and Larissa. To the south is the prefecture of Trikala, southwest is the prefecture of Ioannina and southeast of the prefecture of Kastoria.
It has an area of 2291 km². The landscape of the county, in the main (85%), is mountainous and hilly. Geographically shaped by the mountain ranges of Vourinos, Kamvounion, Hasion and the Northern Pindos, which has the highest peaks of the county. The mountain range extends into the western part of the county and is an impenetrable 'wall', which makes communication difficult
The mountains Vassilitsa (2249 m), Vouzio (2239 m), Aftia (2005 m) Flega (2158 m) Maurovouni (2050 m) and Milea (2160 m) rise on the border of the county with the Ioannina prefecture, while the peaks Kirkouri (1860 m) Skourtza (1799 m) Orliakas (1433 m), Avgo (2177 m) Pirostia (1860 m), are all located entirely within the county of Grevena.
Low mountains, with smooth by eroded peaks, separate Grevena from the prefecture of Trikala. The Kambounia range occupies the northeastern part of the county, with the highest peak Vounasa (1615 m) Mavrolithari (1363 m), Prophet Elias (1055 m) north of Deskatis. Tretimos (1093 m) and Tsiotina (933 m) to the south of Deskati.
On the southwestern border rises Meterizia mountain (1381 m).
There are few open plains in the county, one of the largest is high up, bound by mountains and only accessible via the province of Voio (Kozani). Other small valleys and plains can be found at Karpero, Demeter, Kathakali and Paliouria.
The main river is the Aliokmona which also has several tributaries in the county. The Aliakmonas enters the county from the north, from the region of Siatistas of Kozani. It goes through the forests east of Grevena where it meets a large tributary from the Northern Pindos mountains, the Greveniotikos/Grevenitis/Greveniotiko river which also runs it's course through the city of Grevena. The Venetikos river, the largest tributary, joins the Aliakmonas south of Grevena and Stavropotamos.
The prefecture of Grevena is considered one of the coldest climatic regions of Greece.
Grevena is located nearly in the center of the county and has a radial road network to Kozani, Larissa, Trikala and Ioannina. The city of Grevena is built at an altitude. 534 m east of North Pindos, on the banks of Grevenitis, a tributary of Aliakmona.