Sweden – A visit to the fortress of Vaxholm

The water around the island used to be the main route from the sea to Stockholm.
So in 1544 Gustav Vasa built the first buildings of a fortress to defend the city of Stockholm from naval attacks. The island was attacked by the Danes in 1612 and the Russians in 1719.
http://www.baldhiker.com/2015/02/02/sweden-a-visit-to-the-fortress-of-vaxholm/