King Coil’s Grave

..Ayrshire--divided into the three districts of Cuningham, Kyle, and Carrick--seems to have been the main seat of the families of the race of Coel, from whom indeed the district of Coel, now Kyle, is said traditionally to have taken its name. There is every reason to believe that Boece, in filling up the reigns of his phantom kings with imaginary events, used local traditions where he could find them; and he tells us "Kyl dein proxima est vel Coil potius nominata, a Coilo Britannorum rege ibi in pugna cæso" and a circular mound at Coilsfield, in the parish of Tarbolton, on the highest point of which are two large stones, and in which sepulchral remains have been found, is pointed out by local tradition as his tomb.

From The Four Ancient Books of Wales by William F. Skene [1868], online at

sacred-texts.com/neu/celt/fab/fab012.htm

Lots more here in the 'History of the County of Ayr' v1 by James Paterson (1847).

archive.org/stream/historyofcountyo01pateuoft#page/2/mode/1up