Capel Lligwy has national recognition and statutory protection from alteration as it has been designated as a Grade II listed building – the lowest of the three grades of listing , designating " buildings of special interest , which warrant every effort being made to preserve them " . It was given this status on 2 September 1952 and has been listed because it is " important as a substantially 12th @-@ century structure , with some architectural details surviving from this early period " , even though it is now in a " ruinous condition " . Cadw ( which is responsible for the inclusion of Welsh buildings on the statutory lists ) also notes the " unusual 16th @-@ century vaulted south chapel " .