Eider

Eider, a river of North Germany, forming the boundary line between Sleswick on the north and Holstein on the south, rises south-west of Kiel, and flows in a general westward direction, though with many windings, and enters the North Sea at Tönning, after a course of 117 miles. It is navigable as far as Rendsburg, from which town the Eider Canal (constructed 1777-84) stretches east to Kiel Harbour in the Baltic, thus establishing water-communication between the North and Baltic seas.