A seven-foot tall tomb stone located near Fowey in Cornwall.
Heading towards the coast of Cornwall is a tall obelisk-shaped stone monument resting on a circular base. It has been moved here from the hillfort of Castle Dore, which is believed to have been the home of King Mark in the fifth century.
On it is an inscription which is reported to date from the sixth-century. The inscription, although some what difficult to read now, is believed by some to say,
“Drustanus lies here, son of Cunomorus”
Drustans hic iacet Cunomori filius
Etymologists claim that Drustanus is the Latinization of the Pictish name, Tristan, and that Cunomorus is a Latinization of the name Kynvawr, a historical king who ruled Cornwall in the early sixth century.
“Drustanus” is a form of Tristan, and many scholars have thought to identify Drustanus with the Tristan of legend. The Life of Saint Paul Aurelian connect Cunomorus with Mark by stating that Mark’s full Latin name was Marcus Cunomorus. If these facts are true, history was largely modified by making Mark Tristan’s uncle instead of his father. On the other hand, other evidence suggests that Tristan is actually based on the eighth-century Drust, son of a Pictish king and not this Drustanus.
Source
Physical topography in Britain and elsewhere.