Locmariaquer is a Stone Age site in north-west France distinguished by its two large stone tombs and massive granite standing stone or menhir. The monumental structures, all built within metres of each other, were built in the 5th millennium BCE by the local sedentary farming community and are amongst the most impressive Neolithic monuments anywhere.
The huge igneous stone monolith known as the Grand-Menhir was a single piece of granite 20 metres tall and over 280 tonnes in weight. The engineering skills employed to move and erect such a massive stone are impressive, especially as the nearest source of such stone was 10 km distant. The menhir was carefully positioned, probably using earth ramps, at the end of an alignment of 18 interlocking stones c. 4,500 BCE, now destroyed but indicated at the site today. The menhir would have been finished off and given a smooth surface using quartz hammers. Another large menhir or stele once stood near the Grand-Menhir and two large pieces from it - identified by their ox carvings - were reused in the Table-des-Marchands tomb (tumulus) nearby (see below) and the stone tomb on the small island of Gavrinis across the Gulf of Morbihan 4 km away. The surface of the Grand-Menhir shows deliberate stud marks and a socket was made in the base of the stone to increase its stability when standing. Nevertheless, the giant subsequently toppled over and fractured into four large pieces. Whether this was due to natural causes such as high winds, lightning or an earthquake, or due to a deliberate breakage is unclear. More certain is the fall likely occurred only a few hundred years after its erection, sometime around 4,000 BCE.
The Er-Grah tumulus (or Er Vinglé in the local Breton language meaning 'quarry' and indicating the site's role as a source of building material in later times), located just a few metres from the Grand-Menhir, was probably constructed around 4,200 BCE. The single-person tomb measures 140 metres in length and ranges in width from 16 to 26 metres. Taking a trapezoid shape, the height is relatively modest at no more than 2 metres. The structure evolved over time, starting out in c. 4,500 BCE as a group of small burial mounds and ditches with some dwellings. Later, a rectangular cairn was constructed over the site, which incorporated a huge slab stone as a roof and which is still part of the structure today. In c. 4,000 BCE the cairn was extended using limestone covered with a surface layer matching the existing stones. Due to the acidity of the soil, no human remains have been found in the tomb, but excavations have revealed flint tools, jewellery, and a ceramic dish.
The large stone tomb known as the Table-des-Marchands was constructed c. 4,000 BCE. The monument's name (Table of the Merchants) derives from the huge stone slab incorporated into the roof of the interior chamber (dolmen) which measures 7 x 4 m and is 80 cm thick. The slab was, in fact, first fully-excavated in Roman times and is part of the stone whose other piece was used in the tumulus at Gavrinis. The stone mound at Locmariaquer measures 30 x 25 metres, but its present height is less than half of the original. The inner stone tomb and entrance corridor are made with large flat upright stones topped by horizontal slabs and dry masonry. The corridor allowed for additional burials to be added to the tomb over time. The inner tomb is an impressive 2.5 metres in height and includes a large pointed stone positioned facing the entrance, considered to represent a divinity. This large sandstone stele is covered with linear relief carvings and was originally set near the Grand-Menhir before being used within the tumulus. Other carvings on the interior stones include crooks, oxen, and axe heads.