Hiking in historic archipelago environment

Fredriksborgs Hotell's 18th-century buildings were once officers' residences for the adjacent Fredriksborg Fortress from 1735 - which protected the entrance to Stockholm for just over 100 years. But the area is full of history. Opposite the narrow Oxdjupet is Oscar Fredriksborg's fort from the 1870s which was protected in turn by the "Värmdölinjen" just behind the hotel and which has been marked out as a historical hiking trail.