... and the Afanc
Llyn Barfog is a tiny lake on the hills to the north of the Dyfi, and it was here that a terrible Afanc lived. Now an Afanc is a sort of magical beaver, found in a number of Welsh lakes, and they were far more scary in those days than they are now. Like Really Scary. King Arthur was passing through (yes, I know...) and defeated the Afanc, throwing it into Llyn Cau, which is way up near the summit of Cader Idris, a good few miles to the NE. Another version of the tale recounts that it was in fact Hu Gadarn and his team of wondrous long-horned oxen which dragged the Afanc out of the lake, something he had done before in a number of Welsh locations.
(So who was Hu Gadarn? Some say he was the first druid, others say that he and Arthur were one and the same. Some say he was a god who led the first Celtic settlers to Wales. Others maintain that he was Joshua of Biblical fame, and some even say he was Jesus. At this point I realise that I'm in way over my head, so why don't you just type "Hu Gadarn" into any respectable search engine, and work it out for yourself!)
... and Carn March Arthur
Carn March Arthur is just to the south of Llyn Barfog, being a small rock which bears the actual hoofprint (oh, yes) of King Arthur's horse. Now, I'm not saying this was left there when he defeated the terrible Afanc, but it would seem to fit quite nicely, wouldn't it?
... and the Legend of the Elfin Cow.
For the full story take a look at http://www.sacred-texts.com/neu/celt/wfl/wfl03.htm, but in a nutshell:
Some elfin ladies owned a herd of wonderful white cattle and they used to graze them near Llyn Barfog. A local farmer caught one of the cattle and from it bred an award-winning herd of his own, becoming very rich. Naturally, he had to go and spoil it all by deciding to slaughter the Elfin Cow and, as he hit her, so a furious elfin lady appeared, took the cow back and arranged it such that all of its descendants departed as well, making the farmer so upset that he drowned himself in Llyn Barfog. How twp can a person get. And why is the same story told of Llyn-y-Fan Fach, way down south in the Brecon Beacons?
... and Echo Rock
Just to put the icing on the cake, in addition to all of these great legends about Llyn Barfog, there is a point near the lake where you can produce an excellent echo, and many years ago it was simply marked by a scruffy signpost. I've not been back there for years, but just wonder whether anyone ever goes there now and tries it out. You could shout "Hey, Arthur" or "Hi there, Elfin Cow" or, if you were really brave, "Ya Boo Afanc" - and then take a quick look behind you, just in case. (Whoops, getting a bit carried away there.)
OK, so I've got no talents as a storyteller, but check out the following Web Sites for superb introductions to these legends:
http://www.thelostland.com/ relating to books by famous author Susan Cooper.