There are few lonelier places on earth than a sea fort, especially those manned by only a handful of people at a time. Sea forts have long served as defensive positions, as lighthouses, and as early warning stations; while built, they’re out of necessity prime, peak examples of state-of-the-art engineering. As they age, though, they’re often more trouble than they’re worth to repair, and are left to the elements. This article explores 10 abandoned and repurposed sea forts, anti-submarine towers and other offshore military platforms.

10. Solent Forts, England


The Solent Forts were also known as Palmerston’s Follies. They were built in the late 1800s off the coast of Portsmouth as part of England’s maritime defense network. At the time of their conception, Louis Napoleon was coming to power and emerging not only as Emperor Napoleon III, but also taking the head of a massive army. The government, understandably concerned, commissioned the four forts as early defense.


No Man’s Land, St. Helens (above), Spitbank and Horse-Sands were constructed, but were incredibly short-lived. A fifth fort, Ryde Sand, wasn’t even completed when the area was found to be too unstable to safely support the fort.


Advances in steam power and other technologies made it difficult to keep the forts updated to the point where they were a viable defense system. By the time they were completed, the original threat that they had been built to combat was done. They were used through World War Two mainly as signal and warning facilities, as they weren’t built for the heavy artillery that a fully armed fort would require. They were also used for the seizure of French ships off the coast, but they were ultimately decommissioned in 1956.


Recently, the forts are being given new life. The Horse-Sands Fort is being remodeled and restored to its original condition, with plans to open it as a museum. Spitbank is being converted into a luxury hotel, and No Man’s is getting a face-lift and being turned into a banquet facility, dining hall, spa and cabaret.

9. Maunsell Sea Forts, England


The Maunsell Sea Forts were named for their designer, Guy Maunsell, and they were a crucial part of Britain’s defense network during World War Two. Seven forts – four naval and three army – were built in the Thames estuary, and several can still be seen on the horizon today.

The Army sea forts were a series of seven towers, all connected by walkways to a central control tower. Built beginning in 1942 as anti-aircraft defense, the forts were armed with both gun and searchlight towers. Constructed on land and floated out to sea where they were installed, they were a massive success, and plans were drafted to build more of the towers. Those plans were scrapped in 1952, however, although the towers are still considered among the most successful of the early ancestors of today’s off-shore structures.


Of the three Army forts – Shivering Sands (top), Red Sands (above) and Nore – only two are still standing after the collapse of Nore begun by a 1953 storm that damaged the structure and compromised its integrity; it was later hit by a ship, and ultimately dismantled after the deaths of four civilian caretakers.


The naval forts had two main supports and anti-aircraft guns mounted on the top. Rough Sands, Sunk Head, Tongue Sands and Knock John were all abandoned by the end of the 1940s, but had a brief – and rather weird – period of occupation after that. From 1965 to 1967, the sea forts were, perhaps appropriately, the home of pirate radio stations. The stations, which originally started in fishing boats, were headquartered on all four of the otherwise abandoned naval towers – after the Marine Broadcasting Act was passed, they were replaced by Radio 1 and Radio 2.


Knock John is still in an incredibly good state today. Its guns were only removed in 1992, and all ladders have also been removed from the fort, making it impossible to board – largely due to the idea that it might have been used for smuggling. Originally, there were 49 sea forts planned for construction on the River Thames, and another 38 on the Mersey.

8. Texas Towers, United States