At Castell March it is fabled that King March, one of Arthur's warriors, resided, who had horse's ears.  The same story is told of him as of Midas.  In order to conceal the fact, he killed every barber who trimmed his hair, and then buried him in a swamp.  A piper happened to cut the reeds that grew there, but the pipe would play one tune, "Mae clustiau march i Farch ab Meirchion," and the attendants on the king, regarding this as an insult, fell on the piper and killed him.  But when one of them put the pipe to his lips, again it would play no other tune.  It was then discovered where the reed had been cut, and the whole story came out.
    March was the husband of the fair Iseult, who eloped with Tristan, his nephew.  Twenty-eight knights were sent in pursuit, but failed to catch the runaways.  However, at last they were taken and brought before King Arthur, who decided that Iseult should spend half the year with Tristan and half with March, and it was left to the latter to decide whether he should have his wife with him whilst foliage was on the trees or when they were bare.  He chose the latter, whereupon Iseult exultantly exclaimed, "Blessed be the judgment of Arthur, for the holly and the ivy never drop their leaves, but are ever green; so farewell for ever to King March." (A Book of North Wales, Baring-Gould, 1903)