Carraig á Mhaistin stone
County Cork, Ireland
The Carraig á Mhaistin stone (transl. Bully Rock) is a megalithic tomb located in Cork harbour. It was previously believed to have been an 18th-century folly, built by Murrough O'Brien, 1st Marquess of Thomond, like the nearby Siddons Tower folly.
Archaeological site data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).