More confusion. There's so much magic associated with Taliesin, involving potions, Taliesin's earlier persona turning into a grain of wheat which was eaten by his enemy who happened to be in the shape of a hen at the time (rotten luck), his being re-born, cast away to sea in a coracle, being found stranded upon a fishing weir near Borth, rescued and ultimately developing into the leading bard of his time, a member of King Arthur's Court, around the 6th Century AD. At the end of his life he returned to the area and is popularly said to be buried just above the village now named after him, Tre' Taliesin. Bedd Taliesin looks suspiciously like a barrow/cromlech/cist grave from a much earlier period, reportedly originally in the middle of a stone circle, but now only comprising a large stone slab and a cairn - all the rest seemingly robbed by local builders.
Pics at http://www.aberarchsoc.org.uk/index.php?Id=mon4&Th=1 Aberystwyth & District Archaeological Society's web site, which seems to be down at the moment.
The first written mention is said to be by Edward Lhyud in 1695 in Camden's Britannia, in which he said he was "far from believing that ever Taliesin was interred here". Lewis Morris mentions it in "Celtic Remains" of 1745. Henry Penruddock Wyndham in his "Gentleman's Tour through Wales" (1774) records that "within these five years [it] has been entirely plundered, and the broken stones are now converted to gate-posts", and attributes this act to local religious zealots.
Samuel Meyrick had this to say in 1808: http://www.llangynfelyn.org/dogfennau/bedd_taliesin_mynegiad.html#meyrick
Despite the vandalism, Samuel Lewis's 1833 Topographical Dictionary of Wales stated with some precision that it consisted of 6 large stones forming a chest with a lid, about 6 ft long and 3 ft 6 in wide, surrounded by two stone circles, 27 ft and 31 ft across.
Nicholson in his "Cambrian Travellers' Guide" (1840) measured it out, and in 1847 the Cambrian Archealogical Society did the same. It was noted in 1873 that a great many stones had been removed, and at some stage after this the Dean of Hereford fell in whilst visiting it. The Dean of Bangor, who was also in attendance, displayed admirable solidarity and jumped in alongside him!
There's a story that in the 19th Century there was an attempt to dig out the grave, but a mighty thunderstorm came and frightened the workmen away, never to return.
Read more at:
and http://www.llangynfelyn.org/dogfennau/bedd_taliesin_mynegiad.html - a magnificent Web Site dedicated to the Llangynfelyn area.