Over 5,000 years ago, ancient builders constructed the Brownshill Dolmen, also known as Dolmain Chnoc an Bhrúnaigh, near Carlow in County Carlow, Ireland. This megalithic portal tomb, located about 3 kilometers east of the town, boasts a capstone estimated to weigh around 150 metric tons, making it one of the heaviest in Europe.

Built between 4000 and 3000 BC, the tomb poses an intriguing question: How did the builders, with only primitive tools at their disposal, manage to maneuver such a colossal stone into place? This impressive structure continues to captivate visitors and researchers alike.