Dowan's Hill

From a name of a farm in the immediate vicinity -- Dunree, in Gaelic Dun-righ, signifying the king's stronghold -- it is inferred that the fort was distinguished by a royal appellative.

[..] In former times, Cassillis Downans was regarded as a favourite haunt of the fairies of Ayrshire, and a popular tradition still exists illustrative of their peculiar attachment to the locality. The old house of Cassillis, it is said, was originally intended to have occupied a site on the top of the hill, but the fairies were so much opposed to this that they invariably demolished at night what had been built during the day -- removing the stones and other material to the spot where the castle now stands -- until the proprietor, convinced of the folly of contending with his invisible opponents, at length gave up the contest.