Llyn Llech Owain
Located one mile north of Gorslas in west Glamorgan, Wales, this pool now covers the site of a magic well that never ran dry so long as the stone slab covering it was replaced after water had been drawn from it.
This lake is associated with a legend which states that it must never be allowed to dry up. Myrddin (Merlin) prophesied that, if it did, Carmarthen would suffer a catastrophic disaster.
One day, one of the King Arthur’s knights stopped to drink from the well, but dozed off to sleep and forgot to replace the slab. When he awoke, he found that the well had overflowed and was flooding the surrounding countryside. He hurriedly mounted his waiting horse and quickly rode around the edge of the flood waters, which stopped encroaching over the land when they touched his horse’s hoofs. The resulting lake is still there to be seen today.
See also
Llwch Ewin | The Legend of King Arthur