The Berth and Berth Pool are just outside the town of Baschurch in mid Wales. The site itself is surrounded by marshy lowlands that would have been flooded in Arthur's time (much like Glastonbury) and would have given the earthwork the appearance of an island.
Berth Pool is Phillips and Keatmans' Avalon, the likely burial place of their Welsh "Arthur," Owain Ddantgwyn.
The Canu Heledd, a poem in the Red Book of Hergest, identifies the area around modern day Baschurch as the burial site of the seventh century kings of Powys. Eglwyseu Bassa translates as the "churches of Bassa". Lilly Chitty, an archeologist working here in 1925 heard a local legend that "a prince was buried beneath a mound on the south slope after a great battle and that his men were buried in a longer, narrower mound nearby"
Archeology at Berth Pool has been limited. The hill adjacent to the Pool is called the Berth, may have been where the kings were actually buried. This area has not been excavated and the only recorded artifact was picked up in 1906 when a man working on the banks of a small stream that drained the pool discovered a bronze cauldron dating from the early first century, and is seen as evidence that pagan Celtic peoples cast religious offerings into this pool. Cauldrons held special religious significance in this pagan society, and some scholars have seen such objects as precursors to the Holy Grail .
Arthurian Sites in Wales