The Kiel Canal is a 98-kilometre-long (61 mi) freshwater canal in the German state of Schleswig-Holstein. The canal was finished in 1895, but later widened, and links the North Sea at Brunsbüttel to the Baltic Sea at Kiel-Holtenau. 

An average of 250 nautical miles (460 km) is saved by using the Kiel Canal instead of going around the Jutland Peninsula. This not only saves time but also avoids storm-prone seas and having to pass through the Danish straits.

Besides its two sea entrances, the Kiel Canal is linked, at Oldenbüttel, to the navigable River Eider by the short Gieselau Canal. The Kiel is the world's busiest man-made waterway for seagoing ships, used by a similar number of ships as on the Panama and Suez canals combined.

The canal slices through Schleswig-Holstein, Germany's northernmost state whose Baltic coast capital is Kiel, 90 kilometres north of Hamburg. 

According to en.wikipedia