Part 6/8:
In the wake of World War I, Heligoland was returned to British control under the Treaty of Versailles for a brief period when its military fortifications were dismantled. Once again, the island was reduced to its previous tourist-centric lifestyle.
However, as Adolf Hitler rose to power, Heligoland saw a resurgence of military fortification in anticipation of a global conflict. It was heavily armed with U-boat pens and extensive underground facilities but subsequently proved to be more of a burden than a boon for Germany during WWII.