Sight of Arholma coast

It is not easy to guess that there is an entire underground town with mighty gun. Besides this island other two batteries were built on the islands Bodskär and Nåttarö. They were all scrapped in the early 2000s due to the adoption of a new concept of the Swedish coastal defense. And only this one at Arholma was preserved and in 2008 there is the museum of Coastal Defence was established.