Archaeologists from the North West have started digging up a 5,000-year-old tomb linked to the legendary King Arthur.
The University of Manchester hopes their efforts will answer some of the mysteries surrounding the historic site, known as Arthur's Stone.
And members of the public will be able to see the work themselves by pre-booking tours.
The ancient Arthur's Stone site in Hertfortshire, which is near to the town of Hay-on-Wye along the Welsh-English border, has a Neolithic chambered tomb which has never previously been excavated.
Their work could also shed new light on the legend of King Arthur, the fabled leader of the British who is said to have battled a giant at the site.
The archeologists, working with a team of volunteers from English Heritage, are removing turf to expose and record the sensitive remains.
Manchester Professor Julian Thomas said: “Arthur’s Stone is one of this country’s outstanding prehistoric monuments, set in a breathtaking location - yet it remains poorly understood.
“Our work seeks to restore it to its rightful place in the story of Neolithic Britain”.
The site is close to an area rich in finds which can inform the modern-day British about the daily lives of the island's residents many thousands of years ago.
These include incomplete skeletal remains of several people, together with flint flakes, arrowheads and pottery.Today, only the large stones of the inner chamber remains, which is placed in a mound of earth and stones whose original size and shape remains a mystery.
The chamber is formed of nine upright stones, with an enormous capstone estimated to weigh more than 25 tonnes on top.
Like many prehistoric monuments in western England and Wales, this tomb has been linked to King Arthur since before the 13th century.
According to legend, it was here that Arthur slew a giant who left the impression of his elbows on one of the stones as he fell.Ginny Slade, Volunteer Manager at English Heritage, said: "This excavation gives a really rare and exciting chance for members of the public to come and see archaeology in action.
“Our team of wonderful volunteers will be on hand to explain the latest findings as they happen - we’re asking people to book in advance to make sure everyone has a chance to enjoy this great opportunity.”
Booked tours of the site are available via this link.