Just eight kilometres from Copenhagen harbour lies a piece of living naval history: Flakfortet, an artificial island made of two million tonnes of quarry stone, concrete and sand, strategically placed on Saltholm Flat in the Øresund. Created between 1910 and 1915 as part of Copenhagen's sea defences, it is now one of Scandinavia's most unusual berths. The island and marina are now up for sale.
From the weapons platform to the sailors' meeting place
The history of Flakfortet reads like a maritime adventure novel. Originally designed for a crew of up to 550 men and equipped with heavy guns, the fort was never used in combat during the First World War. After 60 years of service, it was abandoned by the Danish military in 1968 - the weapons dismantled, the casemates abandoned.
But then a second career began: in 1975, the Copenhagen Sailing Union leased the abandoned fortress. The gun emplacements became moorings and the officers' mess became a restaurant. Step by step, the fort developed into a popular excursion destination for sailors, tourists and those interested in culture.
Swedish era to end after almost 25 years
In 2001, the Danish state sold the island to the Swedish company Malmökranen AB for just three million kroner - a sale that raised eyebrows in Denmark. However, the new owners invested around two million euros in the dilapidated facility: modern sanitary facilities for sailors, a restaurant, infrastructure, a ferry connection to Copenhagen as well as a desalination plant for drinking water and generators for a self-sufficient power supply.
Flakfortet was already up for sale once before in 2015 - back then for 56.5 million crowns. But no buyer was found. Now, after almost a quarter of a century in Swedish ownership, the owners are starting a new attempt - ideally, so hopes the commissioned estate agent Stig Lintrup from Lintrup & Norgartback into Danish hands. The price: 74.75 million crowns for 3.1 hectares of artificial island, 9,900 square metres of building space, its own marina and even a helipad.
The monument protection conflict
Particularly explosive for sailors: At the start of the 2018 season, the marina was on the brink of closure. After years of successful operation, the Danish museum administration Slots- og Kulturstyrelsen suddenly demanded that all conversions be restored to their 1995 condition - including the sanitary facilities, without which harbour operations would have been unthinkable. A storm of protest in the social media and from sailing organisations led to the authorities giving in within a month.
The fort has been protected as a cultural monument since 2002. Every structural change has to be agreed with the monument protection authority - a challenge for every future owner, as development plans have to navigate the tension between monument protection and lively use.
A special experience: mooring under the fort
Depending on the starting harbour, the journey takes 20 to 40 minutes through the picturesque Øresund with views of Copenhagen and across to the Swedish coast. The marina is surrounded by a protective breakwater, which was originally built to protect the gun emplacements and today forms a sheltered harbour with clear water.
The kiosk sells shower tokens, food and summer paraphernalia. The restaurant offers buffet and à la carte meals with a view over the sound. The historic bunkers can be visited, and a highlight is the single-cylinder diesel generator, which is over 100 years old. The island attracts up to 50,000 visitors in peak years.
The special charm of mooring under the fort lies in the contrast between green summer land, gloomy casemates and the exposed location in the middle of the sound. The only downside: the mooring fees are comparatively high - a price to pay for the unique location and infrastructure.
What happens next?
According to the operator's website, the 2026 sailing season on Flakfortet will begin as planned on 25 April. Broker Lintrup sees potential buyers among real estate companies with a focus on unique investments, foundations modelled on the neighbouring Middelgrundfortet (now "Ungdomsøen") or wealthy private individuals.
The sales brochure outlines development potential such as glamping offers, cultural events, expanded catering and small festivals. However, one condition from the state sale in 2001 remains: The island must remain open to the public.
For Scandinavia-loving sailors, it remains to be seen whether new owners will find the balance between commercial development, monument protection and the role as a maritime cultural monument - and as a sailors' meeting place.
