Photo: Edgar El·CC BY 3.0· Wikimedia Commons
Islands / Horten / Østøya
Island in the old naval area at Karljohansvern east of Horten, neighbour to Mellomøya. Historically used by the Royal Norwegian Navy.
Østøya is the easternmost of the magazine islands in the naval area at Karljohansvern, straight east of Mellomøya and joined to it by a bridge over Strømsund. It is low and wooded, with old military buildings between the trees. From offshore, Horten and its shipyard town are behind you.
Former and partly military area; check access.
No scheduled boat comes here. You will have to find the nearest public quay yourself, and the rest is your own boat or a kayak. Check the wind and wave forecast before you set out. The open stretches in the outer fjord turn unpleasant in a fresh breeze.
Østøya was originally called Østre Løvøy and was one of the three Løvøy islands: Vestre, Midtre and Østre. The navy bought them in 1819. Vestre Løvøy was sold on to Falkensten Bruk and is called Løvøya today, while the other two became the navy's magazine islands and took the names Mellomøya and Østøya.
Together with Mellomøya, Østøya served the naval base at Karljohansvern as an ammunition area. Powder and ammunition were stored at a safe distance from the shipyard and the town, with water in between. Under the German occupation from 1940 to 1945 the Wehrmacht used the islands the same way. Karljohansvern was the navy's main station from 1850 to 1968, and the shipyard kept up civilian operations until 1987.
Østøya lies in the old naval area at Karljohansvern and is managed together with Mellomøya. Woods cover it, with little building beyond the military traces. Bridges tie it to Mellomøya across Strømsund.
This is a former military magazine area with limited access, so check the current rules before planning a landing. There is no public ferry. No formal access restriction is known in the water around Østøya itself, but neighbouring Mellomøya has a plant conservation area in the east, in force since 30 June 2006.
Østøya, Mellomøya and Løvøya were once three islands all called Løvøy. The navy bought the whole cluster in 1819 and split it with Falkensten Bruk.
The navy put its most dangerous goods out here: powder and ammunition on an island of their own, with water as the safety distance to the shipyard and the town.
Oslo Sea Experience passes Østøya on its private fjord trips from Tjuvholmen.
The Norwegian version notes which facts were taken from each source: Østøya på norsk.