Arwystli

A mountainous region in Wales.

While hunting in the area, Merlin and some other warriors encountered a fountain of pure water with apples lying around it. Merlin collected the apples but, finding that there were not enough to go around, generously distributed them to the other warriors and took none for himself. When the other warriors ate the apples, they promptly went insane.

Merlin later discovered that a jealous woman - who had desired him but who he had rejected - had deliberately poisoned the apples to take revenge on Merlin. Merlin was later able to heal Maeldinus, one of the unfortunate warriors.