Archeologists in England for the first time will excavate Arthur’s Stone—a 5,000-year-old Neolithic tomb named after the Excalibur-wielding ruler of Camelot. The mysterious site in the English countryside is made of a large assembly of rocks and is believed to have been used as a burial chamber, though experts admit little is truly known about the stone construction or why it was built. There are competing theories as to how the spot earned its Arthurian association, but one of the better known tales involves Arthur slaying a giant who fell backward onto the site’s capstone, splitting it in half. “The act of constructing such a massive edifice would undoubtedly have been important, as it would have drawn people together to labor, enhancing social solidarity, and perhaps generating prestige for the person or persons directing the work,” Manchester University archeology professor Julian Thomas told CNN.