The standing stone at Pen-yr-Orsedd is a tall erect monolithic slab 3.9m high by 1.2m wide and 0.2m thick. This may be a prehistoric monument of some kind, possibly a Bronze Age ritual stone, although a more recent date and mundane function are also possible.
A second similar stone stands some 230m to the north (NPRN 302307).

Source: RCAHM Anglesey Inventory (1937), 109

John Wiles 30.08.07