Waun Mawn Standing Stones — Attraction in Eglwyswrw

Waun Mawn (Welsh for "peat moor") is a megalithic site in the Preseli Mountains of Pembrokeshire, Wales. Following excavations in 2018, it became the site of a supposed dismantled Neolithic stone circle. The diameter of the postulated circle was estimated to be 110 m (360 ft), making it the fifth largest diameter for a British stone circle, after Avebury (331.6 m (1,088 ft)), Stanton Drew (113 m (371 ft)), Karl Lofts (estimated 122 m (400 ft)), Long Meg (maximum 120 m (390 ft)), and slightly larger than the Ring of Brodgar (104 m (341 ft)).

The site is located around 1 mile (1.6 km) to the south west of Brynberian. This tract of moorland sits on the southern slopes of the 339 m (1,112 ft) hill top of Cnwc yr Hŷdd ("cock of the corn"), just to the north of the broad east-west ridge of the Preseli range.

There are four stones at the site today, one standing and three prostrate. Nearby are the Troed y Rhiw ("foot of the hillside") standing stones and to the west of the main group is another solitary standing stone, the 'Waun Mawn Stone', measuring some 2.3 m (7 ft 7 in) high.

During 2017 and 2018, excavations by the UCL team of archaeologist Mike Parker Pearson, led to a proposal that the site had originally housed a 110 m (360 ft) diameter stone circle of the same size as the ditch at Stonehenge. The archaeologists also postulated that the circle also contained a hole from one stone which had a distinctive pentagonal shape, very closely matching the one pentagonal stone at Stonehenge (stonehole 91 at Waun Mawn and stone 62 at Stonehenge). Both circles appear, according to some researchers, to be oriented towards the midsummer solstice.

Following soil dating of the sediments within the postulated stone holes, via optically stimulated luminescence (OSL), it has been argued, by Parker Pearson, that the circle of stones was built c. 3400–3200 BC and then, before 2120 BC, was disassembled, dragged across land and reassembled at Stonehenge in Wiltshire, some 140 mi (230 km) distant. Parker Pearson's proposals have been published in the journal Antiquity. This postulated migration of the stones was likened by the researchers to the story told by Geoffrey of Monmouth, in his 12th-century History of the Kings of Britain, of Merlin taking the stones of the Giant's Dance circle in Ireland to Stonehenge.

The site and its connection with Stonehenge was the subject of the BBC Two programme, Stonehenge: The Lost Circle Revealed, with Parker Pearson and Professor Alice Roberts. Broadcast was on 12 February 2021, and reported in New Scientist on 20 February 2021.

Work in 2021 led Pearson and his colleagues to conclude that only 30% of the proposed stone circle at Waun Mawn had been completed, but that perhaps as many as 17 stones had been erected so between eight and 13 had been removed in antiquity, far fewer than the perhaps 80 bluestones that once stood at Stonehenge. That work uncovered no new evidence connecting Waun Mawn and Stonehenge.

Two geological articles published in 2022 proved that there was no link between Waun Mawn and the supposed "bluestone quarries" at Craig Rhosyfelin and Carn Goedog, and no link between Waun Mawn and Stonehenge. In a 2024 study published in The Holocene, Brian John re-examined the geological and archaeological evidence from the site, and concluded that the "lost circle" of standing stones had never existed, and that there was no evidence to demonstrate a link with Stonehenge. He concluded that there had been considerable "interpretative inflation" at the site, driven by a desire to show a...

To remove an existing monument and drag it 140 miles to Stonehenge implies a committed social order and strong common purpose. The idea and actual demonstration of dragging stones over kelp seaweed is far more convincing way of moving them than use of wooden rollers/sledge; particularly because many stone monuments are found close to the sea and an abundance of seaweed. All that is left of the largest stones is 1 standing and 3 fallen, weighing 6 to 8 tons. The sight of the Preseli Mountain to the south east, to cross or go around, give an awe inspiring glimpse of the task undertaken over 5,000 years ago. Wonderful to see and judging by the number of other people visiting, a shared experience. I celebrate that the site is unmarked but it is really so important some additional information would help, such as plot of location of the removed stones, a site plan...

Waun Mawn standing stones have attracted a lot of attention, further enhanced by their confirmation as being the original henge location of Stonehenge's blue stones. The site is easy to access from the B4329 at Tafarn-y-bwlch, although parking in a rough layby is tight, 2-3 cars max. The circle is about 200m along a signposted farm track and then 250m off to the right on a slightly sloping plateau area. There are no signs and no disabled access. There are 4 stones in situ, which are now agreed to form part of the circumference of a henge 110m in diameter. Only 1 stone is standing, 3 recumbent, so not much to see, but the location is magnificent and gives you space to imagine what once was....