The Cliffs of Moher rise 214 metres at their highest point along an eight-kilometre stretch of County Clare coastline, a geology forged from Namurian shale, sandstone and siltstone deposited 320 million years ago when this shelf lay beneath a river delta. Victorian tourists reached the cliffs by horse-drawn coach from Lisdoonvarna; today over 1.5 million visitors arrive annually, drawn by the convergence of vertical strata and open Atlantic, a threshold where sedimentary layers tilt visibly toward the sea and nesting seabirds trace the thermal lift off the rock face. The modern visitor experience was formalised in 2007 when the cliffs secured designation as a signature discovery point on the Wild Atlantic Way, Ireland's 2,500-kilometre coastal touring route. Engineering works anchored observation platforms into the clifftop, and O'Brien's Tower—a round stone structure erected in 1835 by landowner Cornelius O'Brien as a viewing pavilion for his guests—was restored to mark the cliffs' midpoint. The tower stands five storeys high and commands sightlines south to Loop Head, north across Galway Bay to the Twelve Bens, and west toward the Aran Islands lying 13 kilometres offshore. These islands form a limestone threshold to Galway Bay, their karst pavements echoing the Burren plateau that extends inland from the cliffs. Cliffs of Moher cruise from Galway tours depart from coastal villages and harbours along Galway Bay, routing west past Connemara headlands before turning south toward the Clare coast. Vessels hold between 50 and 200 passengers and approach the cliff base where wave-cut platforms expose the sedimentary banding absent from the clifftop vantage. Puffins, razorbills and guillemots nest in the rock ledges between April and July; kittiwakes occupy the upper tiers. The cliff strata dip five degrees seaward, a tilt produced by tectonic compression during the Variscan orogeny that shaped much of northwestern Europe's Carboniferous bedrock. The cliffs anchor the southern boundary of the Burren and Cliffs of Moher Geopark, a UNESCO-recognised landscape encompassing 530 square kilometres of karst topography, subterranean drainage and glacial erratics. The geopark designation in 2011 formalised protections for the cliffs' geological and ecological features, including the Special Protection Area status granted under the EU Birds Directive. Combined cruise and clifftop itineraries allow dual perspectives—one from sea level where the rock face appears as a single unbroken wall, the other from the clifftop paths where the strata fragment into headlands and the visitor centre sits recessed into the hillside to minimise its visual footprint against the horizon.