Grainne’s Grave is situated at this location in Aghnacally is a megalithic wedge tomb, Gallery grave erected c.2,250 BC. As described in The ‘Archeological Inventory of County Cavan (Site No. 6) (Dublin: Stationary Office, 1995), it is situated in an open space in a plantation on the north west flank of Slieve Rushen.
The gallery, 4m long is slightly higher and wider at its open south west end. Two orthostats form the north side and three the south side. The backstone is set beyond the ends of the gallery sides. A massive slab, split in two, covers all but the south west end of the gallery. A tree rooted in peat on top of the roofstone may have caused the break.
There are four outer wall stones to the north of the gallery and two lines of outer walling.
The structure is incorporated in a mound measuring 9m by 7.5m. Local folklore about the cromlech is found in the 1938 Duchas Collection.