It is now protected as a rare example of civil defence planning, built for a war which was greatly feared but thankfully never came.
Mae’n awr wedi ei warchod fel enghraifft brin o gynllunio Amddiffyn Sifil, a adeiladwyd ar gyfer rhyfel a ofnid yn fawr ond, diolch i’r drefn, na ddigwyddodd.