Yes it is.But the scholars of Arthurian legends never leave their texts for empirical research. So they cry foul and stick tpo the dastardly false tale that Avalon was in the South of England.
Goodrich located Arthurs Castle, on an islet at the West of the ISle of Mann . Its called Peel Castle, and it was once joined to the mainland by only a stone bridge that had a drawbridge, under which was a set of pointed blades ready to impale those who fell....The Sword Bridge of Legend.
The ancient foundations of Arthur’s castle are still there under later constructions.