The Ayres National Nature Reserve is an 8-kilometre stretch of low sand-dune and shingle coastline running from Cronk-y-Bing to the Point of Ayre, the island's northernmost tip. Its centrepiece is an expanse of lichen heath -- known as 'grey dune' for the colour the lichens give the ground -- a habitat found nowhere else on the island and only in scattered patches elsewhere in the British Isles. The reserve's shingle beach is the only place on the Isle of Man where little terns breed, alongside linnets, lapwings and skylarks, and grey seals haul out along its shores; the Point of Ayre itself carries the island's oldest lighthouse, near the closest spot on the Isle of Man to mainland Britain.