|Struma (Струма), Strymónas (Στρυμόνας)|
The course of the Struma in Bulgaria and Greece
|Country||Bulgaria, Greece, Macedonia, Serbia|
|Main source||The south slopes of Vitosha, Bulgaria
2,180 m (7,150 ft)
|River mouth||Aegean Sea, Greece
|Basin size||10,797 km2 (4,169 sq mi) in Bulgaria|
|Length||415 km (258 mi)|
The Struma or Strymónas (Bulgarian Струма, pronounced [ˈstruma], Greek Στρυμόνας [striˈmonas], Turkish (Struma) Karasu 'black water') is a river in Bulgaria and Greece. Its ancient name was Strymōn (Greek: Στρυμών [stryˈmɔːn]). Its catchment area is 10,800 km². It takes its source from the Vitosha Mountain in Bulgaria, runs first westward, then southward, enters Greek territory at the Kula village. In Greece it is the main waterway feeding and exiting from Lake Kerkini, a significant centre for migratory wildfowl. The river flows into the Strymonian Gulf in Aegean Sea, near Amphipolis in the Serres regional unit. The river's length is 415 km (of which 290 km in Bulgaria, making it the country's fifth longest).
Parts of the river valley belong to a Bulgarian coal-producing area, more significant in the past than nowadays. The Greek portion is a valley which is dominant in agriculture, being Greece's fourth biggest valley. The tributaries include the Rila River, the Dragovishtitsa, the Blagoevgradska Bistritsa, the Konska River, the Sandanska Bistritsa and the Angitis.
The Ancient Greek city of Amphipolis was founded near the river's entrance to the Aegean, at the site previously known as Ennea Odoi (Nine roads). When Xerxes I of Persia crossed the river during his invasion in 480 BC he buried alive nine young boys and nine maidens as a sacrifice to the river god. The forces of Alexander I of Macedon defeated the remnants of Xerxes' army near Ennea Odoi in 479 BC. In 424 BC the Spartan general Brasidas after crossing the entire Greek peninsula sieged and conquered Amphipolis. According to the ancient sources, the river was navigable from its mouth up to the ancient (and today dried) Cercinitis lake, which also favored the navigation; and thus was formed in antiquity an important waterway that served the communication between the coasts of Strymonikos Gulf and the Thracian hinterland - almost to the city of Serres.
The Battle of Kleidion was fought by the river in 1014. In 1913, the Greek Army was nearly surrounded in the Kresna Gorge of the Struma during the Second Balkan War. The Bulgarians were defeated in the war, however, and the Treaty of Bucharest resulted in significant territorial losses for Bulgaria.
The river valley was part of the Macedonian front in World War I. The ship Struma, which took Jewish refugees out of Romania in World War II and was torpedoed and sunk in the Black Sea, causing nearly 800 deaths, was named after the river.
The river's name comes from Thracian Strymón, derived from IE *sru "stream", akin to English stream, Old Irish sruaimm "river", Polish strumień "stream", Lithuanian straumuoe "fast stream", Greek reuma "stream", Albanian rrymë "water flow", shri "rain".
The name Strymón, was a hydronym in ancient Greek mythology, referring to a mythical Thracian king that was drowned in the river. Strymón was also used as a personal name in various regions of Ancient Greece during the 3rd century B.C.
- Struma Glacier on Livingston Island in the South Shetland Islands, Antarctica is named after Struma River.
- Herodotus 7,114 . The history may be Greek slander, though, as human sacrifice is not known as an Iranian cultic practice.
- Dimitrios C. Samsaris, Historical Geography of Eastern Macedonia during the Antiquity (in Greek), Thessaloniki 1976, p. 16-18 -  Δημήτρης Κ. Σαμσάρης, Ιστορία των Σερρών κατά την αρχαία και ρωμαϊκή εποχή, Θεσσαλονίκη 1999, σ. 55-60 (Ιστoσελίδα του Δήμου Σερρών)
- Katičic', Radislav. Ancient Languages of the Balkans, Part One. Paris: Mouton, 1976: 144.
- Grimal P. .Classical mythology. iley-Blackwell, 1990. ISBN 978-0-631-20102-1.
- Antoninus (Liberalis), Celoria Francis. The Metamorphoses of Antoninus Liberalis: a translation with commentary. Routledge, 1992 ISBN 978-0-415-06896-3.