This massy Stone measuring 12 Feet one way and 6 another, which must from the specifick Gravity of like Solids, weigh betwixt 30 and 40 Ton-weight; by the Inhabitants of the Country is called the Giant's Load, and the Native Irish tell a strange Story about it, relating how the whole was brought all at once from the neighbouring Mountains, by a Giant called Parrah bough McShagjean,and who they say was buried near this Place.
The Grave or Cell of Stone-work they shew for it is about 20 Feet long and 5 Broad, and several Bones of a monstrous Size they affirm to have been dug up there.
From 'Louthiana' by Thomas Wright (1758).
In 'The Legend of Proleek' J H Lloyd is appalled by the "barbarous spelling" of the giant's name above. He deduces from the following story that it may really be 'Para beaj Mac Seroin' *here as below I am having to use the English versions of the Gaelic letters. I think he tries to explain the discrepancy by saying 'beaj (beag)' is 'small' and mor is 'large', it's a sort of ironic / sarcastic name to call a giant 'small'.
[The legend] is recorded in the Ordnance Survey Letters of Co. Louth. The names of the two humble, painstaking scholars who noted it down should be mentioned. They are T. O'Conor and J. O'Keeffe, to whom the antiquarian work in Co. Louth was entrusted. Their letter, dealing with the Parish of Ballymascanlan, contains the following:-
"In Proleek T. L. (*Prailic) is a Giant's grave 7 yards long, 2 1/2 yds. broad at the shoulders, and 1 1/2 yds. at the feet. The head points to the S. and the feet to the N. Large stones fixed in the ground defend the grave on every side; there is one large stone across the feet which
--"scarce ten men could raise,
Such men as live in these degen'rate days."
They say it is the grave of (*Para burde mor Mac Seordin), a Scotch giant, who came to challenge Fin Mac Coole, and of whom they tell a story similar to the story of Feardhiadh. Para buidhe mor asked Fin's wife where he (Fin) used to eat; Fin, she told him, when he was hungry would kill one of those bullocks (pointing to them), roast him and eat him. Para went and did the same; the spot on which he killed, roasted, and ate the bullock, is pointed out yet; it is a hollow in a green field a little to the South of the grave. When he had eaten he went to the river which runs near the spot, to satisfy his thirst; but Fin threw the poison into the river, by which means he despatched him.
A little to the North of the grave there is a large stone computed by the people to be 60 tons weight, supported on three smaller rude stones. It is in some places 6 ft. from the ground, in others 8 ft., and it is said to have been fixed by Fionn Mac Cumhail and Para buidhe mor Mhac Seoidin."
The Legend of Proleek, JH Lloyd. In 'Journal of the County Louth Archaeological Society' vol 1, no.3, Sept 1906.
In the same volume there's an article on 'Louthiana: Ancient and Modern' by Henry Morris. He says:
The small stones seen in the illustration on the top of Proleek Cromlech have been thrown up there in obedience to a curious belief. Young unmarried people, chiefly of the fair sex, throw up three stones on the cromlech in order to find out if they will get married within a year. Owing to the rounded back of the cromlech it is very difficult to fix a stone on the top, but if the consultor of this oracle succeeds in placing the three stones on the top he or she is almost certain of marriage; one or two placed above denotes a probability, while if all the stones fall the chances are nil.
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.