Since the time when Greek sentinels lit fires on mountaintops for the use of mariners at sea, lighthouses have aided the navigation of sailors on European waters. Those crude fires have been replaced by state-of-the-art towers equipped with satellite technology, and lighthouses remain indispensable navigational aids. For Ireland, the lights are important not only to mariners, but to the livelihood of the entire island. Eighty lighthouses under the authority of the Commissioners of Irish Lights dot the 2000 miles of Irish coastline. Each is addressed here, and thirty of the most interesting lights are featured with detailed histories and full-color paintings by noted maritime artist William Trotter. From the sinking of the Lusitania to the burial of a shipwrecked elephant, Kevin McCarthy outlines the significance of Irish lights to the maritime history of Ireland and the world while painting a vivid picture of the life led by the keepers and inhabitants of the rocks, islands, and shores of the Emerald Isle.