Killard national nature reserve, County Down: More famous for its butterflies, this area also details the movements of an ice sheet that froze all of Ireland
A wrinkle of tide is creeping up the lugworm-stippled beach. If I half-close my eyes, sand and sea are a single hazy surface, which skylines the Isle of Man in the distance. I’m at Mill Quarter Bay, whose name hints at undercurrents that belie the calm. Indeed, this place was once crowded with mills harnessing the tide as it churned through the Narrows of Strangford Lough. Other clues to what has carved the area remain: the Angus Rock lighthouse; the markers and buoys dotting the waters; the brick-red of the low cliffs.
I make my way across seaweed-tasselled rocks towards the cliffs. Bearded drapes of sward hang down to the gaping pockmarks of sand martin nest-burrows. A fence braces against an impending slide. The face reveals shifts not just of water but of ice. This is glacial till, mixed with the soft clay of a former seabed. Killard’s peninsula is cherished locally for its butterfly-garlanded wildflowers. However, its national importance rests on its account of the disintegration of the last great ice-sheet that froze all of Ireland and most of Britain during the late Pleistocene.