The Opava ( cs, Opava, pl, Opawa, german: Oppa) is a

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of ...

in the north-eastern

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

, a left tributary of the

Oder The Oder ( , ; Czech, Lower Sorbian and ; ) is a river in Central Europe. It is Poland's second-longest river in total length and third-longest within its borders after the Vistula and Warta. The Oder rises in the Czech Republic and flows ...

river. It originates at the confluence of Bílá (White), Střední (Middle) and Černá (Black) Opava in Vrbno pod Pradědem and runs over 110 km (69 mi) to the Oder at

Ostrava Ostrava (; pl, Ostrawa; german: Ostrau ) is a city in the north-east of the Czech Republic, and the capital of the Moravian-Silesian Region. It has about 280,000 inhabitants. It lies from the border with Poland, at the confluences of four riv ...

, with some 25 km (16 mi) forming the border with

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...

. Its basin area is about 2,090 km², of which 1,814 km² in the Czech Republic. After the

First Silesian War The First Silesian War (german: Erster Schlesischer Krieg, links=no) was a war between Prussia and Austria that lasted from 1740 to 1742 and resulted in Prussia's seizing most of the region of Silesia (now in south-western Poland) from Austria. T ...

, by the terms of the Treaty of Breslau in 1742, the Opava in the Duchy of Troppau became the border between

Austrian Austrian may refer to: * Austrians, someone from Austria or of Austrian descent ** Someone who is considered an Austrian citizen, see Austrian nationality law * Austrian German dialect * Something associated with the country Austria, for example: ...

and

Prussian Prussia, , Old Prussian: ''Prūsa'' or ''Prūsija'' was a German state on the southeast coast of the Baltic Sea. It formed the German Empire under Prussian rule when it united the German states in 1871. It was ''de facto'' dissolved by an e ...

Silesia (the later

Province of Silesia The Province of Silesia (german: Provinz Schlesien; pl, Prowincja Śląska; szl, Prowincyjŏ Ślōnskŏ) was a province of Prussia from 1815 to 1919. The Silesia region was part of the Prussian realm since 1740 and established as an official p ...

). After

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

the demarcation was confirmed by the 1919 Treaty of Saint-Germain-en-Laye as the border between

Czechoslovakia , rue, Чеськословеньско, , yi, טשעכאסלאוואקיי, , common_name = Czechoslovakia , life_span = 1918–19391945–1992 , p1 = Austria-Hungary , image_p1 ...

(

Czech Silesia Czech Silesia (, also , ; cs, České Slezsko; szl, Czeski Ślōnsk; sli, Tschechisch-Schläsing; german: Tschechisch-Schlesien; pl, Śląsk Czeski) is the part of the historical region of Silesia now in the Czech Republic. Czech Silesia is, ...

) and the

Second Polish Republic The Second Polish Republic, at the time officially known as the Republic of Poland, was a country in Central and Eastern Europe that existed between 1918 and 1939. The state was established on 6 November 1918, before the end of the First World ...

Towns

* Vrbno pod Pradědem *

Krnov Krnov (; german: Jägerndorf, pl, Karniów or ''Krnów'') is a town in Bruntál District in the Moravian-Silesian Region of the Czech Republic. It has about 23,000 inhabitants. Administrative parts The town is made up of town parts of Pod Bezr ...

Opava Opava (; german: Troppau, pl, Opawa) is a city in the Moravian-Silesian Region of the Czech Republic. It has about 55,000 inhabitants. It lies on the river Opava. Opava is one of the historical centres of Silesia. It was a historical capital of ...

* Kravaře *

References

Rivers of the Moravian-Silesian Region Rivers of Poland Moravian-Silesian Region Rivers of Opole Voivodeship Czech Republic–Poland border International rivers of Europe Border rivers {{Poland-river-stub