In an area of forest to the southeast of the summit, near Ballyedmonduff, at grid reference O 185 213, there is a Bronze Age wedge tomb, known as the Giant's Grave. It is considered one of the finest examples of a wedge tomb in Ireland: the antiquarian John O'Donovan said of it, I doubt I have met so perfect a pagan grave in any other counties hitherto examined. Its appearance has changed since the time of its first discovery: sketches made in the 1830s by the Ordnance Survey show a grass-covered tumulus. A drawing by George Du Noyer indicates that the roof was partially intact at that time. In addition, the pine forest that now surrounds the site obscures the views of the Great Sugar Loaf mountain and the twin tors of Two Rock that would have been possible from this location in the past. The tomb was first opened in 1832 by Alderman Blacker of St Andrew Street, Dublin but no record of this excavation survives. However, when John O'Donovan visited on behalf of the Ordnance Survey, the locals told him that ashes had been found when the grave was opened. After the tomb was opened, many of the larger stones were removed by local stonecutters. The site was excavated again in 1945 by Seán P. Ó Riordáin and Rúaidhri de Valera who found sherds of decorated Beaker pottery, a polished hammer, a possible polishing stone and a flint scraper. A small amount of cremated human bone was also found. Following the excavation the monument was rebuilt in the form it appears in today. The tomb consists of a burial gallery over long divided into three chambers surrounded by a horseshoe-shaped arrangement of stones with a straight façade at the western end. At the southern end is a long stone with seven cupmarks on one surface. This form of rock art is usually associated with earlier Neolithic culture and is generally found on natural rock outcrops. The stone may have come from a natural boulder brought to the site during construction.