Y Garreg Siglo Bardic Complex is an scheduled anicient monument which consists of a bardic monument or gorsedd possibly dating to the 18th century. The monument is associated with the leaders of the Celtic revival.

The first and innermost group of twelve stones was erected around 1795 by Edward Williams, also known as Iolo Morganwg, probably modelled on the nearby prehistoric ring cairn. The rocking stone or Y Garreg Siglo at the centre was the focal point for Bardic ceremonies. After Williams' son Taliesin ap Iolo died in 1847, the Gorsedd was revived by Evan Davies, also know as Myfyr Morganwg, who extended the complex in 1849 for his inauguration as Archdruid of Glamorgan. He added a concentric ring of large stones about 14m in diameter around the first twelve stone. Pairs of parallel sinuous lines of smaller stones extend as an avenue in either direction from the circle for some 30m to north-west and south-east, in the form of a serpent. The serpent's head to the north-west has two carved stone 'eyes' and one surviving slab from an arrow-shaped nostil. The carvings on the right eye form concentric circles, and those on the left are the first ten letters of the Bardic alphabet.

The monument continued to be used for Eisteddfodau and ceremonies until the 1920s and was a focal point for meetings of nationalists and the labour movement. Evan and James James, composers of Mae Hen Wlad Fy Nhadau, were admitted to the Gorsedd there in 1850.

The monument is of national importance as an exceptionally early and complex monument of the Bardic revival, retaining significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. The structure itself may be expected to contain archaeological information concerning chronology and building techniques.

Reference: Cadw SAM description.

RCAHMW, 2023.