The Cliffs of Moher are spectacular sea cliffs in the Burren in County Clare. They run from O'Brien's Tower to Hag’s Head, so called because a legend relates how a sea-witch, Mal of Malbay, fell in love with the Irish hero, Cú Chulainn and chased him across Ireland. Cú Chulainn escaped by hopping across sea stacks as if they were stepping stones. Mal, however, not being so nimble lost her footing and was dashed against the cliff.
At their southern end, the Cliffs rise 390 feet above the Atlantic Ocean and 5 miles to the north, they reach their maximum height of 702 ft. From the cliffs, and from atop the tower, you can see the Aran Islands in Galway Bay, the Maumturks and Twelve Pins mountain ranges to the north in County Galway, and Loop Head to the south
The cliffs take their name from an old promontory fort called Mothar or Moher, which once stood on Hag's Head. Promontory forts are defensive structures above a steep cliff, often only connected to the mainland by a small neck of land, thus using the topography to reduce the ramparts needed. They mostly date from the Iron Age, although some in Ireland are thought to be Bronze Age.
The official Cliffs of Moher Coastal Walk runs for 18 km, from Hag's Head to Doolin, passing the Visitor Centre and O'Brien's Tower, with good viewing throughout, though that is obviously weather dependent 😀
The cliffs consist mainly of beds of Namurian shale and sandstone, with the oldest rocks being found at the bottom of the cliffs. During their formation between 313 to 326 million years ago, a river dumped sand, silt and clay into an ancient marine basin. Over millions of years, the sediments collecting at the mouth of this ancient delta were compacted and lithified into the sedimentary strata preserved in the now-exposed cliffs.
They are a haven for wildlife from grey seals to porpoises, dolphins, minke whales and basking sharks. On land, feral goats, foxes, badgers and the Irish hare are found
The Cliffs have featured in a couple of famous films such as The Princess Bride (1987) as the filming location for "The Cliffs of Insanity" and Harry Potter and the Half-Blood Prince (2009)