The mountains are Orvelos to the north, Menoikio to the east, Pangaio to the southeast, Kerdylio to the southwest, Vertiskos to the west, parts of Krousi to the west and portions of the Kerkini lies to the northwest. The regional unit borders on Thessaloniki to the southwest, Kilkis to the west, North Macedonia with the Novo Selo Municipality to the northwest, the Blagoevgrad Province of Bulgaria to the north, Drama to the northeast and Kavala to the east. The Strymonian Gulf lies to the south along with the Strymonas delta. Lake Kerkini was a lake located in the southern portion which is now drained. 41% of the regional unit are arable and most of the lands are near the Strymonas river which flows from Bulgaria and empties into the Strymonian Gulf. Another river is the Angitis in the eastern part of the regional unit, with the ravine and caves near Alistrati. The regional unit has many archaeological and historical features including Serres, Amphipolis, several monasteries, and Metaxa near the border with Bulgaria. The regional unit is also a tourist attraction including Lailia, rich in forests, a skiing resort in the central portion, lake Kerkini which is a reservoir supplying water to the farmlands. Fishing is common within Ano Poroia especially during the summer months and famous Alistrati's caves and the nearby Aggitis ravine. The southern part around the Strymonas valley has a Mediterranean climate, the rest is predominantly continental with cold winters in higher elevations.
History
In modern times, Serres, like the rest of Macedonia was contested territory between Greece, Bulgaria, Serbia and the Ottoman Empire. After its liberation from the Turks by the Bulgarians in the First Balkan War, Serres became a part of Greece at the end of the Second Balkan War. During the National Schism, it was occupied by Bulgaria again only to form part of Greece at the end of the war. During the Second World War Bulgaria occupied Serres and launched a campaign of Bulgarisation. It was liberated in 1944. A substantial portion of the population of the regional unit are descendants of refugees which came from Eastern Thrace which is now Northwestern Turkey, Asia Minor and from Pontus during the Greco-Turkish War.
Administration
The regional unit Serres is subdivided into 7 municipalities. These are :
Amfipoli
Emmanouil Pappas
Irakleia
Nea Zichni
Serres
Sintiki
Visaltia
Prefecture
As a part of the 2011 Kallikratis government reform, the Serres regional unit was created out of the former Serres Prefecture. The prefecture had the same territory as the present regional unit. At the same time, the municipalities were reorganised, according to the table below.
