Dig at medieval castle reveals lost relic from the Cold War

The outlook post, which would have been used by the Royal Observer Corps, was discovered by English Heritage volunteers.

The bunker is said to have been one of around 1,500 used across the conflict and would have been used to track the threat of nuclear bombs during the Cold War in the 1960s.

Constructed as a key defence mechanism to hold off attack, the posts were built almost identical to each other, with communications facilities and bunk beds for members of the ROC, a civil defence organisation largely made up of volunteers.

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Its location, in the grounds of Scarborough Castle in Yorkshire, has remained hidden ever since it was closed off and buried in the around 1968.

It was uncovered by workers at English Heritage last weekend after it was identified through data analysis and a ground survey.

Images released by the charity show the brickwork fully intact with the wording Scarborough engraved into one of the blocks.

Kevin Booth, head of collections at English Heritage, gave an insight into its location and why it was used as a strategic tool.

He said: "Wherever you lived in Britain you were probably no more than a few miles from an ROC post – yet few people knew they existed. 

"It seems strange to have a Cold War bunker built inside Scarborough Castle, but in many ways, it is a perfect location.

"This headland has been an observation post for thousands of years, from a Bronze Age settlement to a Roman signal station, medieval castle, WWI gun battery and, here, a 1960s concrete bunker watching for Armageddon."

The search was supported by the National Lottery Fund, whose director Helen Featherstone said: "It's really exciting that this lost bunker has been uncovered by the team working on this project marking 100 years of the Royal Observer Corps.

"This find builds on our understanding of their story and shines a spotlight on their important work protecting the UK.

"The project has been made possible thanks to money raised by National Lottery players, and I'm sure that they will be thrilled to know that they have played a role in this discovery."

Scarborough Castle wasn't hit or targeted during the Cold War, but was used as a base by the ROC to monitor potential nuclear explosions.