According to research by Alan Wilson and Baram Blackett this area is the burial site of Arthur I - born around AD 344 and died around AD 400.
King Arthur I was the eldest son of Emperor Magnus Maximus, the only son of Crispus Nobilis Flavius Caesar, who was the eldest son of the British Emperor Constantine the Great and the British Queen Minerva, whose ancestry goes back to Emperor Constantius Chlorus and the British Empress Helen of the Cross.
Arthur I was the chief general of Magnus Maximus, and invaded Gaul in AD 383, capturing Paris the stronghold of the Lady St.Genevieve - who becomes Lady Guinevere of the confused Romantic Arthurian
This Arthur - copiously recorded in ancient Manuscript genealogies and known in British Manuscripts as the King of Greece - then defeated the massed armies of the Roman Emperor Gratian at Soissons, and chased him South to Lugdunum (Lyons), where he killed him. The campaigns of this Arthur I through Switzerland and on down through Italy, over to Greece, and up into the Balkans are well known and recorded. He fought two major battles against Theodosius of Constantinople in Illyria = Yugoslavia, where he was greatly outnumbered and finally defeated.
Arthur I known in Latin as Andragathius made his way back to Britain in AD 388.
The second Arthur was of course Arthur II son of King Meurig (Maurice) son of King Tewdrig, and so on back to Brutus. He was a sixth generation direct male line descendant of Arthur I.