The Cliffs of Moher are where Ireland ends and the open Atlantic begins — a 14-kilometre wall of dark rock that rises sheer to 214 metres, roughly the height of a 60-storey building above the waves. The stone records a far older world. Around 320 million years ago, rivers poured mud, sand and silt into a vast tropical delta, much as the Mississippi does today, and the sediment hardened into the banded shale, siltstone and sandstone you can read across the cliff face. Look closely at the flagstone and you can still find the burrows and feeding trails of creatures that once crawled those mudflats — trace fossils whose makers science has never firmly named. In 1835 the local landlord Cornelius O'Brien crowned the highest point with a small round viewing tower that still stands.
Walk the cliff-edge path and there is no mistaking where you stand: the sheer drop, the buffeting wind and the boom of surf far below press in from every side, and on a clear day the Aran Islands float on the horizon out in Galway Bay. From late spring the ledges erupt with noise and colour as up to 30,000 pairs of seabirds nest here — guillemots, razorbills, kittiwakes and Ireland's largest mainland colony of puffins, which gather on the grassy sea-stack of Goat Island below the main viewpoint. The wall faces due west into the ocean, so the best light comes in the evening, when the low sun turns the rock copper and the sea glitters all the way to the horizon. This is now Ireland's most visited natural attraction, drawing around 1.5 million people a year and anchoring the Burren and Cliffs of Moher UNESCO Global Geopark; filmgoers know the wall too, as the 'Cliffs of Insanity' from The Princess Bride.