Reasons for Designation
Portal dolmens are funerary and ceremonial monuments of the Early and Middle Neolithic period, the dated examples showing construction in the period 3500- 2600 BC. As burial monuments of Britain's early farming communities, they are among the oldest visible field monuments to survive in the present landscape. Where sufficiently well-preserved, they comprise a small closed rectangular chamber built from large stone slabs, with free-standing stones flanking the frontal slab of the chamber. A capstone, often massive, covers the chamber, and some examples show traces of a low cairn or platform around the chamber. Some sites have traces of a kerb around the cairn and certain sites show a forecourt area, edged by a facade of upright stones in a few examples. Little is yet known about the form of the primary burial rites. At the few excavated sites, pits and postholes have been recorded within and in front of the chamber, containing charcoal and cremated bone; some chamber contents of soil and stones may be original blocking deposits. Many portal dolmens were re-used for urned cremations, especially during the Middle Bronze Age. Only about 20 portal dolmens are known nationally, concentrated in west Penwith, Cornwall, and in the north-west Oxfordshire Cotswolds, with a scatter between these. As one of the few surviving field monument types of the Neolithic period, and due to their rarity, considerable age and longevity of construction and use, all
portal dolmens are considered to be nationally important. Despite partial early excavation and the limited preservation of the enclosing mound, the portal dolmen known as 'The Three Brothers of Grugith' survives comparatively well, especially considering its great age and fairly prominent location. It is one of a nationally rare group of monuments. It will contain archaeological and environmental evidence relating to its construction, longevity, funerary practices, ritual and social significance and its overall landscape context
Details
The monument includes a portal dolmen called 'The Three Brothers of Grugith' or 'Grugwith' situated close to the summit of a prominent hill overlooking Goonhilly Downs. The dolmen survives as two upright parallel orthostats supporting a large capstone enclosing an area measuring approximately 4m long, 2m wide and 1m high. Shallow depressions on the surface of the capstone have been interpreted as either cup-marks (early prehistoric rock art) or natural features. The chamber was excavated by Borlase in 1872, and he discovered a pit approximately 1m deep and a single flint flake. There is debate as to whether one of the upright stones is natural. There is little surface evidence for an enclosing mound.
Sources: HER:-
PastScape Monument No:-426455
