Yxnøy and the area surrounding Tønsberg Barrel were fortified by the German occupation forces during World War II. Bunkers, trenches and other remains from the war can still be seen in the surrounding area. A number of ships have also sunk here, including ships such as Wilhelm Tell in 1851 and Bjørgvin in 1961, which lies 70 meters from Tønsberg Barrel. In 1907, the ship Union sunk here and its crew of eight men drowned. The coastal hiking trail from Tønsberg Barrel to Skjellvika Beach is 9 km. It is part of the international North Sea Trail. Yxnøy is the only place in Norway where the plant species (Valeriana dioica) occurs. Strandvika Nature Preserve is located at Yxnøy. It is home to a black alder swamp forest containing ramsons, iris pseudacorus and early purple orchid. The nature preserve was established in 1980. History Østerøya was fortified during World War II. Beaches Beaches on East Island include: Skjellvika Flautangen Nordre Trubervika Strandvika Yxnøy Ertsvika Hagaløkka Tallakshavn See also Vesterøya (West Island) References Peninsulas of Vestfold og Telemark Sandefjord