Dora II (Dora 2) is an unfinished German submarine base and submarine pen or bunker in Trondheim, Norway, which is next to Dora I (Dora 1). Construction of the bunker (designated by the Germans as DORA II) was undertaken during the Second World War, but the complex was never finished unlike Dora I. Trondheim was traditionally referred to as Drontheim in German, and the name DORA is the letter "D" in the German phonetic alphabet.[1]