Lewis Chessmen is the oldest known Chess pieces in existence, carved from walrus ivory. Seventy-eight pieces were found in a stone chamber in a sand bank on the west coast of the Isle of Lewis in 1831. They date back to 1150-1170. The pieces were discovered by a peasant who found a mysterious stone building buried under several feet of sand. The pieces reside in the British Museum and the National Museum in Edinburgh. The most striking piece is the Rook, which is the form of a captain afoot, rather than a castle.