St. Mary's Lighthouse is on tiny St Mary's Island, just north of Whitley Bay on the coast of North East England. The small rocky tidal island is linked to the mainland by a short concrete causeway which is submerged at high tide. It was decommissioned by Trinity House in 1984. While it no longer functions as a working lighthouse, it is easily accessible (when the tide is out) and is regularly open to visitors; in addition to the lighthouse itself there is a small museum and visitor's centre.