Jutland is a peninsula in Northern Europe that forms the continental portion of Denmark and part of northern Germany (Schleswig-Holstein). It stretches from the Grenen spit in the north to the confluence of the Elbe and the Sude in the southeast. The historic southern border river of Jutland as a cultural-geographical region, which historically also included Southern Schleswig, is the Eider. The peninsula, on the other hand, also comprises areas south of the Eider: Holstein, the former duchy of Lauenburg, and most of Hamburg and Lübeck.