Avalon Camelot King Arthur:  Trevethy Quoit, also known as #King #Arthur&#39;s Quoit, is an impressive burial chamber in Cornwall. It stands over 15 feet and dates from the Bronze Age. The capstone is pierced by a hole, the purpose of which is unknown. A portion of the front entrance stone is also missing; this may have been cut to leave an entrance into the chamber. The whole structure may at one time have been covered with a mound of earth long since degraded by the changing seasons.