The UK's giant 78ft metal towers that stand abandoned in the sea

is home to many fascinating places, from historic cities like and to . But there is another spot that many people might not have heard of. It's off the mainland and standing in water roughly seven miles from the coast. Known as the Maunsell Forts, these eerie steel structures were built in the Thames and Mersey estuaries during the to help defend Britain from German attacks.

According to , they were designed by civil engineer Guy Maunsell and came in two forms: naval forts and army forts. The naval forts were made up of two hollow reinforced concrete towers connected by a large steel platform. They were constructed onshore, floated to their locations, and then sunk onto sandbanks. These forts stood between 60ft and 78ft tall and housed crews of around 120 men and were armed with heavy anti-aircraft guns.

The army forts, including the Red Sands and Shivering Sands towers near the Kent coast, consisted of seven steel towers arranged in a defensive formation.

These were linked by metal walkways, and each had guns, searchlights, and crew quarters to defend against enemy aircraft.

In total, seven fort groups were built, but only a few remain standing today.

Several were lost to the sea or dismantled after being decommissioned in the late 1950s.

According to , during the war the Thames Estuary forts shot down 22 enemy aircraft and 30 flying bombs.

But by the 1960s, they had found a new use as pirate radio stations. Broadcasters set up "illegal" stations on the towers, using them to beam music to the mainland.

One of the most well-known was Radio Essex, launched by Paddy Roy Bates on Rough Sands Fort.

Bates later declared the platform to be an independent nation, naming it the Principality of Sealand - a self-declared micronation that still claims to exist today.

Others like Radio City and Radio 390 also operated from the towers before government crackdowns shut them down in the late 1960s.

Today, the towers are mostly abandoned. A 2021 structural inspection found the Red Sands Fort to be severely damaged, with parts of it already falling into the sea.

While it's no longer safe to climb, visitors can still see it from the water. According to , tours run from the Kent coast to the Red Sands towers during the warmer months.

The £40-per-person boat trip takes passengers out to the forts and offers a chance to view them up close and take photos from all angles.