The Dortmund–Ems Canal is a 269 km long canal in Germany between the inland port of the city of Dortmund and the sea port of Emden. The artificial southern part of the canal ends after 215 km at the lock of Herbrum near Meppen. From there, the route goes over a length of 45 km over the river Ems until the lock of Oldersum. There, the canal continues with a further artificial part of 9 km. This was made because the types of ships at the time of the construction of the canal were not built for open sea, at the Dollart and the entry to the sea port of Emden. This part of the canal is connected to the Ems-Jade Canal from Emden to Wilhelmshaven.
The canal was opened in 1899. The reason for the construction of the canal was to lighten the load on the railways, which could not transport the products of the Ruhr area. Also, the canal was supposed to make the coal from the Ruhr area more competitive, compared to the imported English coal. Furthermore, the steel industry in the eastern Ruhr area needed ores from abroad.
The canal was attacked numerous times during World War II due to its strategic importance. An attack in September 1943 by 617 Squadron RAF (the "Dambusters") was unsuccessful and costly. The squadron attacked it again in September 1944 using Tallboy "earthquake" bombs breaching it and causing considerable damage. It was repaired after the conflict.