At their southern end, they rise 120 metres (390 ft) above the Atlantic Ocean at Hag's Head, and, 8 kilometres (5 miles) to the north, they reach their maximum height of 214 metres (702 ft) just north of O'Brien's Tower,[4] a round stone tower near the midpoint of the cliffs, built in 1835 by Sir Cornelius O'Brien,[2][5] then continue at lower heights.

In the 1990s the local authority, Clare County Council, initiated development plans to enable visitors to experience the cliffs without significant intrusive man-made amenities.

The centre was planned to be environmentally sensitive in its use of renewable energy systems including geothermal heating and cooling, solar panels, and grey water recycling.

To counter this, visitors are increasingly encouraged to come at other times, with discounts given to coach operators who book for off-peak slots, and late opening of the centre introduced for July and much of August.

Later-arriving visitors have also been facilitated by the fitting of automatically opening exit gates from the official car parking facilities.

"[19] 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.

During the time of their formation between 313 and 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.

Individual strata vary in thickness from just a few centimetres to several metres, each representing a specific depositional event in the history of the delta.

[29] These include Atlantic puffins, which live in large colonies at isolated parts of the cliffs and on the small Goat Island,[29] and razorbills.

[30] A wide range of sea life can also be seen, from grey seals through porpoises, dolphins, minke whales and basking sharks, as well as, occasionally, sunfish.

[33] The cliffs are mentioned in the Martin Scorsese film Bringing Out the Dead (1999) and are noted in the 2008 documentary Waveriders as the location of a large surfing wave known as "Aileens".

[37] Bus Éireann route 350 links the Cliffs of Moher to several locations: Ennis, Ennistymon, Doolin, Lisdoonvarna, Kinvara and Galway.