By what collective name are the North Sea islands of Hauptinsel and Dune better known?
British Administration of Heligoland Hellgoland Helgoland Helgioland Helgoland Power Cable Island of Helgoland Heligoland British Heligoland
island of helgoland helgoland power cable helgoland heligoland british heligoland hellgoland british administration of heligoland helgioland
heligoland
WikipediaEntity
Heligoland