Britain's first atomic bomb was built in Foulness 70 years ago

Its military links means there are strict rules in place on how many times you can visit, and indeed which bits of the island you can even go to.

The secretive side of the island was never more important than the years after the Second World War, when Britain began hatching plans that would see it become the world's third biggest nuclear power.

It was on June 5, 1952, that Britain’s first ever atomic bomb was moved from Foulness to Shoebury, and onto a barge at Gunners Park.

Explosive Preparation Lab X6 - where Britain's first nuclear bomb was assembled

The devastating weapon was later handed over to a royal navy shop bound for Australia, where it would be taken to a remote island and detonated.

The bomb itseld was developed at the former Atomic Weapons Research Establishment on Foulness, which is only located about five miles north-east of Southend.

The base is among just a handful of sites in England associated with the development of nuclear weapons and its history spans the full duration of the Cold War.

Aerial - The base in 1956

The building was specially constructed in 1947 on the direction of a small secret cabinet committee within Clement Atlee’s government, who decided it was time to add the atomic bomb to Britain’s arsenal.

The project was codenamed Operation Hurricane and saw components of the bomb delivered to Foulness in 1952 where they were then assembled.

It was 70 years ago yesterday that the now partially assembled bomb was taken by lorry to Shoebury and then by barge from Gunners Park to HMS Plym, moored at Stangate Creek, Sheerness.

The site was targeted by protestors

HMS Plym then sailed for eight weeks to the test site, the Monte Bello islands, off the northwest coast of Australia.

Lacking open, thinly-populated areas at home, British officials chose the overseas location to test the weapon.

It took eight weeks after arrival to construct the structures and equipment needed to test the weapon.

The bomb was finally detonated on Friday, October 3, 1952, producing an estimated yield of 25 kilotons - four kilotons greater than the atomic bomb dropped on Nagasaki in August of 1945.

To test the effects of a ship-smuggled atomic bomb on a port, the bomb was exploded inside the hull of Plym, anchored 350 metres off Trimouille Island.

With the success of Operation Hurricane, Britain became the third nuclear power after the United States and the Soviet Union.

The test left the island uninhabitable for decades. By the 1980s the radioactivity had decayed to the point where it was no longer hazardous visitors, however the island remained a prohibited area until 1992.

Back on Foulness, rumours about the work being done at the atomic research facility were beginning to spread, and led to a number of passive resistance protests which resulted in dozens of people being arrested and sent to prison in 1960.

Hundreds of police had to be drafted into the scene as members of the ‘Direct Action Group against Nuclear Armament’ tried to stop lorries and vehicles from reaching the Atomic Weapons Research facility.

The men and women - aged from their twenties to their seventies - showed their ‘passive resistance’ by laying down in the road at Wakering in an attempt to blockade access to Foulness Island, where they feared nuclear weapons testing was taking place.

No official word on the work being done on the island was ever given by officials at the time, aside from assurances to the public that no dangerous nuclear materials were being used on Foulness.

The base itself was open for 50 years and was a place of work for hundreds of people throughout the years.

It eventually closed in 1997 and has only helped add to the sense of mystery and secrecy that surrounds the remote lands of Foulness.