This is the artist's copy of carvings on an ornamental bone plaque found at Cadbury Hill Fort in England, one site believed to be the location of the legendary Camelot. The original carving is this same size but has no color on the knots. The knots themselves seem to meander in a freeform way irrespective of any strict grid. It has been dated to the 11th century, long after Arthur's time, of course, but in the same neighborhood and therefore quite exciting!
— Ref: Photo # 91 from "Was This Camelot?" by Leslie Alcock