Kiel Canal, artificial waterway, 61 mi (98 km) long, in Schleswig-Holstein, N central Germany, connecting the North Sea with the Baltic Sea. At sea level, the canal extends from Kiel on the Baltic to Brunsbüttelkoog at the mouth of the Elbe River. Locks at each end of the canal minimize tidal variation. Built (1887–95) to facilitate movement of the German fleet, the Kiel Canal was widened and deepened from 1905 to 1914. Large oceangoing ships can pass through the canal. Because of its great military and commercial importance the canal was internationalized by the Treaty of Versailles (1919), though its direct administration was left with the Germans. Hitler repudiated its international status in 1936, but free navigation in the canal was returned after World War II. The canal is also known as the Kaiser Wilhelm Canal, for William II of Germany, and as the North Sea-Baltic Canal (Ger. Nord–Ostsee–Kanal ). Today the canal is a major passage for shipping in the Baltic region.