Copenhagen, Denmark

Flakfortet, meaning sand-shoal fortress, is a sea fort located on the artificially built island of Saltholmreb. Flakfortet was the last of three artificial islands that the Danes created to defend the entrance to Copenhagen's harbor (the other two are Trekroner Fort and Middelgrundsfortet). Eventually Flakfortet became more of a site for anti-aircraft weapons than for coastal artillery. Its military functions ended in 1968.

The fort was built in the years 1910–1914 as part of Copenhagen's sea-fortifications. The island is 23 meters high and covers 32,000 m2. Construction of the artificial island required the use of caissons of reinforced concrete, possibly the first use of such structures. The caissons were first cast at Lynetten quai on Refshale Island, thought the last was cast at Flakfortet itself.

Flakfortet is now used for recreational purposes such as concerts, and the site has a restaurant and yacht moorings. During the summer, a ferry company, Spar Shipping, has five scheduled trips per day to the island, with the trip from Nyhavn taking about 40 minutes each way. There is an overnight hostel on the island too.



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Copenhagen, Denmark
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Founded: 1910–1914
Category: Castles and fortifications in Denmark


4.4/5 (based on Google user reviews)

User Reviews

Simon Jorissen (12 months ago)
I visited the island briefly with a amall sailing boat and some friends on a really sunny day. The location is pretty idyllic and a beer in the sun is really nice. However, upon departure, 30 minutes after our arrival, we were chased out of the harbour by a grumpy harbour clerk that had us pay 120 kr havnepenge for mooring half an hour. He was very upset and intimidated us with his larger motor vessel by coming really close. I paid by MobilPay because I was scared he was going to damage my vessel. I haven’t had an experience like that in many years of sailing abroad.
L B (2 years ago)
Wonderful little destination to sail out to
Allan Andreasen (2 years ago)
Travel by boat, relaxing and getting some fresh air before arriving at the fort. Definitely worse a visit and it is possible to enjoy a dinner and get a guided tour.
Hans Olav Nymand (3 years ago)
Nice food in the resraurant but snall selection of beers. The treasure hunt worked ok. Interesting place.
Michal Kkkk (3 years ago)
Nice place for short stop
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