Built around 4,000 BCE by the first farmers in Ireland, the Brownshill Dolmen outside Carlow is the largest dolmen in Europe. The megalithic portal tomb comprises two portal stones and a gate stone supporting a massive, 150-ton granite capstone that slopes down to the ground.
There are tens of thousands of these ancient stone monuments all over the world, but no one knows exactly who built them or why. The current archaeological consensus is that they were portal monuments leading to burial chambers, but after thousands of years of erosion, looting and natural movements, only the stone doorways remain.
Officially called Kernanstown Cromlech, the Brownshill Dolmen is thought to be between 4,900 and 5,500 years old, and experts believe that it was once the site of religious rituals. As there are no plans to excavate this site, we may never know the true purpose or extent of this dolmen. Some theories suggest that it served as the tomb of a local chieftain, while others say it was used as a border marker.