(As usual when it comes to Ireland I am being a bit pathetic with pinning the stories to locations. But I hope the locations still exist).
.. Avowedly malignant ceremonies have been performed at two, if not three, places in East Clare. At Carnelly, near Clare Castle, at an unknown period remote even in 1840, "a black cock, without a white feather," was offered to the Devil on the so-called "Druid's Altar," two fallen pillars near an earthen ring beside the avenue, --to avenge the sacrificer on an enemy, but in this case it brought an equivalent misfortune on the sacrificer himself.
The Duchess de Rovigo, an heiress of the last Stamer of Carnelly, used the story, combined with irrelevant family legends and pseudo-archaeology, in a poem dated 1839, but I obtained it, as given above, from a more reliable source, her mother, in 1875 and 1882, as well as from my brothers and sisters, who heard it in "the forties".
When I was at the dolmen near the house at Maryfort in 1869, an old servant, Mrs. Eliza Ega (nee Armstrong), said to me, -- "Don't play at that bad place where the dhrudes (druids), glory be to God! offered black cocks to the Devil!"
A Folklore Survey of County Clare (Continued)
Thos. J. Westropp
Folklore, Vol. 22, No. 1. (Mar. 31, 1911), pp. 49-60.
A Survey of Monuments of Archaeological and Historical Interest in the Barony of Bunratty Lower, Co. Clare by William Gerrard Ryan
This part of the thesis discusses the various types of monuments of archaeological and historical interest that were noted in the Barony of Bunratty Lower, Co. Clare. Each type of site is examined in turn, under the headings: distribution, features, dating and related sites in Ireland.