The Baltic Sea coast in the east of Schleswig-Holstein is marked by bays, fjords, and cliff lines. Rolling hills (the highest elevation is the Bungsberg at ) and many lakes are found, especially in the eastern part of Holstein called the Holstein Switzerland and the former Duchy of Lauenburg ("Herzogtum Lauenburg"). Fehmarn is the only island off the eastern coast. The longest river besides the Elbe is the Eider; the most important waterway is the Kiel Canal which connects the North Sea and Baltic Sea.