One of the most recognizable and most frequently visited places in Ireland is the Cliffs of Moher.

An excerpt from the article 39 facts about Ireland

The cliff, made of limestone and sandstone, is approximately 14 km long; at its highest point, it reaches a height of 214 m. The cliffs are the western part of the Burren plateau, on their top stands a 19th-century stone tower - O'Brien's Tower, built as a tourist attraction and observation point.