Tradition assigns [King Arthur a] Cornish castle as a hunting seat, viz. the old earth-round of Castle-an-dinas, near St. Columb, from whence it is said he chased the wild deer on Tregoss Downs.
p87 in
Cornish Folk-Lore. Part II [Continued]
M. A. Courtney
The Folk-Lore Journal, Vol. 5, No. 2. (1887), pp. 85-112.