Local Tradition holds that if you successfully land one stone in three on top of the capstone you will be married before the year is out. It also claims that the giant, Parra Bui MacShane, lies here after his fatal encounter with Finn McCool.
From The Gap of the North by Noreen Cunningham & Pat Mcginn.
(From a very interesting Manuscript Volume of Tours by Thomas Stringer, Esq. M.D. of Shrewsbury)
On the lands of Ballymac Scanlan, in the county of Louth, is a large Rath, and on it a great stone, having in the centre a cross with four smaller ones. About thirty yards from the Rath is an entrance into a cave, running under the Rath, but it has not been explored. Tradition calls this the tomb of McScanlan. At the same place are three great pillars supporting a ponderous impost: this was the pensile monument of the northerns. It was called the Giant's Load, being brought altogether from a neighbouring mountain, by a Giant, according to tradition.
Museum Europæum; or, Select antiquities ... of nature and art, in Europe; compiled by C. Hulbert (1825). Online at Google Books.
The megalithic dolmen at Proleek, located in the legendary Cooley Peninsula, is one of the finest examples in Ireland, and is widely photographed and documented.