Ireland - Archaeological Ensemble of the Bend of the Boyne

"The three main prehistoric sites of the Brú na Bóinne Complex, Newgrange, Knowth and Dowth, are situated on the north bank of the River Boyne 50 km north of Dublin. This is Europe's largest and most important concentration of prehistoric megalithic art. The monuments there had social, economic, religious and funerary functions." 

Source: UNESCO World Heritage

Ireland - Skellig Michael

"This monastic complex, perched since about the 7th century on the steep sides of the rocky island of Skellig Michael, some 12 km off the coast of south-west Ireland, illustrates the very spartan existence of the first Irish Christians. Since the extreme remoteness of Skellig Michael has until recently discouraged visitors, the site is exceptionally well preserved." 

Source: UNESCO World Heritage