© Flickr/Creative Commons

Relics from the past - The shores off the coast of the UK are filled with the remnants of past wars and conflicts. These bizarre structures have since been re-purposed in a number of unexpected ways.

© Shutterstock

Maunsell forts - These constructions are named after the man who built them, Guy Maunsell, a WWII civil engineer. They lie in the mouth of the Thames estuary.

© Shutterstock

Construction - They were originally built in 1942-3, and were first assembled and then sunk into the channel, in a similar way to an oil rig.

© Getty Images

Defense from invasion - They served the vital purpose of repelling German aerial attacks, as well as preventing enemy forces from laying mines in the Thames estuary.

© Getty Images

Decommissioned - They were operated up until the 1950s, when they were decommissioned. They were then abandoned and left to fall into disrepair.

© Getty Images

Radio - As the ‘60s began to change the British cultural landscape, the British government still held control over the radio.

© Getty Images

Cultural landmark - Enterprising music pioneers, like John Peel, saw the perfect opportunity to make their mark on the British airwaves.

© Getty Images

Pirate radio - They took to international waters to broadcast from pirate radio stations, from boats and other offshore structures.

© Getty Images

Squatters - Taking advantage of their location, groups of music enthusiasts took over the abandoned sea forts and started broadcasting rock and pop music, outside of the jurisdiction of the British government.

© Shutterstock

Pirates - A number of radio stations operated from the sea forts, Radio Sutch, Radio City in Shivering Sands, Radio Invicta and Radio 390 from Red Sands. Fort Roughs was home to Britain’s Better Music Station.

© Getty Images

Trouble among pirates - However, the good times didn’t last. Fights broke out among the groups occupying the forts, over broadcasting rights and funding. This culminated in the death of Reginald Calvert (pictured).

© Getty Images

Death - After fight over control of the pirate radio station, he went to Oliver Smedley's (pictured) house to confront him. When he arrived, Smedley shot him.

© Getty Images

End of an era - Calvert's widow attempted to keep Radio City running, but after the negative publicity surrounding the case, the British government passed the Marine Broadcasting Offences Act in 1967, outlawing pirate radios.

© Getty Images

HM Fort Roughs - Like in the other forts, Fort Roughs was not free from drama. It was initially occupied in 1965.

© Public domain

Violent seizure - Paddy Roy Bates, a former army major, had been broadcasting from Knock John tower, a Maunsell sea fort he had seized from Radio City.

© Getty Images

Britain's Better Music Station - He then moved to Fort Roughs in 1967, initially intending to continue broadcasting from there. However, with the enforcement of the Marine Broadcasting Offences Act, he could no longer do so.

© Getty Images

Principality of Sealand - Instead, Bates declared the fort to be the Principality of Sealand, seeking to establish Fort Roughs as a micro-nation.

© Shutterstock

Recognition - After a conflict with workmen attempting to reach a navigational buoy near the platform, Bates and his son were brought to a British court to face weapons charges, which the judge dismissed, citing lack of jurisdiction as the "principality" lay in international waters.

© Getty Images

Constitution - Bates considered this to mean de facto recognition of his micro-nation. He created a currency, passports and even a constitution.

© Getty Images

Takeover - A group of mercenaries attempted to take the tower in 1978, led by German lawyer Alexander Achenbach. The invasion failed, and Achenbach was captured. The German government had to negotiate with the self-declared nation for his release, as the British government refused to intervene.

© Getty Images

Fire - Bates died in 2012, and the principality is continued by his son, Michael. It has since suffered a serious fire, and file-sharing site The Pirate Bay has also attempted to purchase it in 2007.

© Public domain

Disrepair - The forts continue in a state of abandonment. In 200,5 artist Stephen Turner, who creates projects on abandoned places, spent one month in the searchlight tower of Shivering Sands fort.

© iStock

Future plans - The future of the sea forts is uncertain, though there have been proposals suggesting that they be transformed into a luxury hotel.

© Shutterstock

Other sea forts - The WWII-era structures are not the only sea forts in the UK. The Solent forts, situated off the coast of Portsmouth, were built during the Napoleonic wars in order to protect Britain from potential invasion.

© iStock

War - They never actually saw any action, and have since been re-purposed for different uses.

© iStock

Party venues - No Man's fort and Spitbank fort have been renovated and offer luxury accommodation.

© iStock

Spitbank - The fort has more than 40 rooms, and has hosted festivals, dance parties and wedding receptions. It even has it's own swimming pool.

© Shutterstock

No Man's Land - The slightly-bigger No Man's Land fort was sold for over a million in 2009. It now operates as a luxury hotel.

© iStock

St Helens - Other forts in the Solent include St Helens and Horse Sand fort. Horse Sand fort was not renovated and a few years ago was placed on the market for £1 million.

© iStock

Day trip - St Helens is accessible by foot at low tide, and at the lowest tides of the year there is a mass walk from St Helens beach.

© iStock