The Roupel Gorge or Roupel Pass (; ) is a steep river valley in the northern part of

Central Macedonia Central Macedonia ( ; , ) is one of the thirteen Regions of Greece, administrative regions of Greece, consisting the central part of the Geographic regions of Greece, geographical and historical region of Macedonia (Greece), Macedonia. With a ...

, immediately south of the Greek-Bulgarian border.Енциклопедия "България", Издателство на Българската академия на науките, том 5, София 1986, с. 836 It was formed by the

Strymon River The Struma or Strymonas (, ; , ) is a river in Bulgaria and Greece. Its Ancient Greek, ancient name was Strymon (, ). Its drainage area is , of which in Bulgaria, in Greece and the remaining in North Macedonia and Serbia. It takes its source fr ...

, which stems from the

Vitosha Vitosha ( ), the ancient ''Scomius'' or ''Scombrus'', is a mountain massif, on the outskirts of Sofia, the capital of Bulgaria. Vitosha is one of the symbols of Sofia and the closest site for hiking, alpinism and skiing. Convenient bus lines and ...

mountains and flows into the

Aegean Sea The Aegean Sea is an elongated embayment of the Mediterranean Sea between Europe and Asia. It is located between the Balkans and Anatolia, and covers an area of some . In the north, the Aegean is connected to the Marmara Sea, which in turn con ...

. The gorge is rich in

biodiversity Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...

which may be endangered by the project to build the Motorway 25 which is a part of

European route E79 European route E 79 is a road part of the International E-road network. It begins in Miskolc, Hungary and ends in Thessaloniki, Greece, also running through Romania and Bulgaria. The road is long. Itinerary The E 79 routes through ...

. Strymon enters from Bulgaria into Greece west of village

Promachonas Promachonas (, , ) is a village and a former community in the Serres (regional unit), Serres regional unit, Macedonia (Greece), Macedonia, Greece. Since the 2011 local government reform it is part of the municipality Sintiki, of which it is a mun ...

, going through Roupel Pass, that it opened up, between the mountains

Belasica Belasica ( Macedonian and Bulgarian: , also translit. ''Belasitsa'' or ''Belasitza'', Ottoman Turkish: بلش Turkish: ''Beleş''), Belles (, ''Bélles'') or Kerkini (, ''Kerkíni'';), is a mountain range in the region of Macedonia in Southe ...

and Orvilos. Here the ground gets flatter so the Strymon loses speed and splits into two branches. The western branch goes to

lake Kerkini Lake Kerkini ( – Limni Kerkini) is an artificial reservoir in Central Macedonia, Greece that was created in 1932, and then redeveloped in 1980, on the site of what was previously an extremely extensive marshland. Lake Kerkini is now one of the ...

and then flows southeast where it rejoins the eastern branch near to the village of Lithotopos. The pass was fortified in 1914–1916, and the Roupel Fortress played a major role in World War I events in Greece and in the

German invasion of Greece The German invasion of Greece or Operation Marita (), were the attacks on Kingdom of Greece, Greece by Kingdom of Italy, Italy and Nazi Germany, Germany during World War II. The Italian invasion in October 1940, which is usually known as the Gr ...

in 1941.

References

Canyons and gorges of Greece Landforms of Serres (regional unit) Landforms of Central Macedonia {{CMacedonia-geo-stub