The Havel Canal, or Havelkanal in German

German language

German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

, is a canal

Canal

Canals are man-made channels for water. There are two types of canal:#Waterways: navigable transportation canals used for carrying ships and boats shipping goods and conveying people, further subdivided into two kinds:...

 in the German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 state of Brandenburg

Brandenburg

Brandenburg is one of the sixteen federal-states of Germany. It lies in the east of the country and is one of the new federal states that were re-created in 1990 upon the reunification of the former West Germany and East Germany. The capital is Potsdam...

. It provides an alternate route to the River Havel

Havel

The Havel is a river in north-eastern Germany, flowing through the German states of Mecklenburg-Vorpommern, Brandenburg, Berlin and Saxony-Anhalt. It is a right tributary of the Elbe river and in length...

, between Hennigsdorf

Hennigsdorf

Hennigsdorf is a town in the district of Oberhavel, in Brandenburg, Germany. It is situated north-west of Berlin, just across the city border, which is formed mainly by the Havel river.-History:...

 and Paretz, thus avoiding a passage through the waterways of Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

 between Spandau

Spandau

Spandau is the fifth of the twelve boroughs of Berlin. It is the fourth largest and westernmost borough, situated at the confluence of the Havel and Spree rivers and along the western bank of the Havel, but the least populated.-Overview:...

 and Potsdam

Potsdam

Potsdam is the capital city of the German federal state of Brandenburg and part of the Berlin/Brandenburg Metropolitan Region. It is situated on the River Havel, southwest of Berlin city centre....

.

Construction of the canal was authorised by the government of East Germany in April 1951. After an extraordinarily short construction period of 13 months, the canal was opened in June 1952, thus allowing East German vessels to avoid transiting parts of the River Havel within the political control of West Berlin

West Berlin

West Berlin was a political exclave that existed between 1949 and 1990. It comprised the western regions of Berlin, which were bordered by East Berlin and parts of East Germany. West Berlin consisted of the American, British, and French occupation sectors, which had been established in 1945...

. Besides its political and military advantages, the canal also allowed large vessels to avoid the (then) small lock at Spandau and reduced the distance travelled by 9 kilometres (5.6 mi).

The canal has a length of 34.9 kilometres (21.7 mi) and has a single lock at Schönwalde

Schönwalde-Glien

Schönwalde-Glien is a community in the Havelland district, in Brandenburg, Germany.-History:The municipality shared its borders with the former West Berlin, and so during the period 1961-1990 it was separated from it by the Berlin Wall....

, with a vertical drop of around 2 metres (6.6 ft).