[3] The building of the tomb dates back to the Neolithic Period, 4000-2500 BC, when waves of colonising farmers migrated to Ireland from the continent.
The entrance to the main chamber is located at the centre of an imposing megalithic facade on the west side of the court.
The chamber is made up of two large compartments divided by a pair of jambs which presumably supported an inner lintel like those at Shawley and Croaghbeg in County Donegal.
Twenty-seven workers were involved in the dig, many being local labourers hired under an innovative State employment scheme.
Three pits within the chamber contained small amounts of cremated bone, which Hencken thought must be symbolic deposits.
[2] The remains of eight neolithic pots, including an example of a cardial ware vessel were found in sub chamber B on the north side of the western end of the cairn.
A smelting pit or blast furnace from the Early Christian period was discovered east of and close to the entrance to the neolithic chamber.
[2]Within the chamber of the monument, Hencken uncovered a very large hearth or fire pit lined with flat flags.
The hearth contained the bones of ox, sheep, pig, dog and fish as well as periwinkle and limpet shells.
The east side of this fire pit was lined with stake holes, which Hencken thought were part of a wattle structure presumably used as a wind-break.
"Plainly Chambers CI and C2 were used as a dwelling in Early Christian times in connection with the contemporary traces in the court.
[2] The large lintel stone, which was found lying within the chamber, originally stood upright creating an imposing monumental facade.
He had the massive lintel stone lifted and placed horizontally over the door jambs in its current position in order to excavate the chamber.
[2] However, a watercolour of the monument painted by William Wakeman in August 1880 shows the lintel standing upright over the entrance.
Though the story that this stone over the entrance from the court into Chamber CI once stood erect like a pediment sounds very improbable, it is generally believed in the district, and it was also told by Mr. John Hannon of Creevykeel.
It is incidentally worth mentioning that, had the stone ever stood erect, it could have been pushed over by three men, but certainly not if it lay flat as we replaced it.