National Geographic : 1946 Nov
Above These Housetops of Helgoland, British and German Planes Met inBattle Roofs of the Unterland (Plate III), the harbor, and Diine Island beyond are seen from atop the heights. Once abig white chalk cliff stood between Helgoland and Dune Island, forming a snug harbor. More than two centuries ago a violent storm swept away the cliff. Since then, Diine has been slowly disintegrating. To make Helgoland the "Gibraltar of the North Sea," the Germans dumped millions of tons of sand from the Elbe estuary intoan area surrounded byretaining walls. The naval base, guarding the Elbe and Weser approaches to Hamburg and Bremen, was likened to "a dagger pointing at England."