Locations used included castles at Cardiff, Caerphilly and Castell Coch, Wales; Peckforton castle, Cheshire; and St Michael's Mount and Roche Rock, Cornwall. St. Govan's chapel on the Pembrokeshire coast was also featured.
The mysterious Green Knight appears before King Arthur's court in the New Year and demands the head of Sir Gawain as the prize in a bizarre game. Given a year's grace, Gawain sets off in search of the Knight for a rematch.