The Rocking Stone or "Y Maen Chwyf" in Welsh is a glacial boulder remaining from the Ice Age. It formed the central point for a "Gorsedd" or "Gathering of Bards" in 1814, which was organised by stonemason, Edward Williams, known as "Iolo Morganwg".
The Gorsedd Circle of smaller stones was constructed in 1849 by Evan Davies, Bardic name "Myfyr Morganwg" and has often been used for Bardic gatherings, and as a focal point for other public occasions.