Bosiliack Chambered Cairn


Having so many prehistoric monuments in such a relatively small area as the Penwith can mean that sometimes something rather special gets overlooked. I was sitting beside Bosiliack Cairn recently, eating my picnic and enjoying the last bit of sun. In the distance Lanyon Quoit was attracting a steady stream of visitors, as was Men an tol which I had passed on my way. Suddenly a group of walkers came through the gate from Ding Dong’s Greenburrow engine house on the path to Lanyon and I was surprised to see that as they passed not one gave this stunning cairn so much as a cursory glance. (I felt like shouting ‘Hey, you are missing something amazing here!’ – but that would have been weird I guess.)

Bosiliack : Boshoulieck, 1303 : translates as ‘sunny dwelling’.

Craig Weatherhill

This early Bronze Age chambered cairn, also known as an entrance grave, stands on a slight ridge close to an ancient hut circle settlement and surrounded by a prehistoric field system. What makes this cairn so special is not just its unusual design and important positioning in the landscape but the fact that it is one of very few of this type of monument which has been excavated in recent times. In the early 1980s there was a particularly destructive fire on this part of the moor and a large number of archaeological features were exposed. The excavation that followed means that we are able to date Bosiliack cairn fairly precisely. It was built between 3710 to 3520 years ago (at the time of writing).

Scillonian Style

Bosiliack cairn has a wonderful kerb of seventeen large upright granite stones lining the edge of the monument. This design is indicative of what is known as the Scillonian Group or Scillonian style of cairn.

“The barrows of the Scilly Group are edged with a well-built revetment wall of orthostats and large course stones which in almost every site is not covered over . . .

Glyn E. Daniel, The Prehistoric Chamber Tombs of England & Wales, 1950

Bosiliack is a rare example of a Scillonian style entrance grave on mainland Cornwall. Around 70 of these chambered tombs have been identified on the Isles of Scilly and then a few at sites on the Penwith which are all considered part of the same group, including Pennance, Brane, Treen, Trewavas, Tregeseal, Chapel Carn Brea and Bosiliack.

“No one is certain whether the mainland entrance grave fashion was spread across to the islands or vice-versa.”

This style of monument is unlike anything found anywhere else in England, although there are some similar examples on the Isle of Man and in Scotland and Ireland. Apart from the upright kerb stones another distinguishing feature of the Scilly Group is the length of the actual internal chamber, which is often significantly longer than other similar monuments. The passage is rarely less than the radius of the mound and can be as long as the diameter of the cairn. At Bosiliack the cairn is 5m across and the passage or chamber is 3m long.


These unique anomalies have led some to propose an interesting theory. It has been suggested that the reason all these tombs bear such unusual similarities is because they were all designed by the same architect. I find this a fascinating idea, that one man or woman was the master craftsman but wonder if the building of all these tombs can be narrowed down to the timeframe of just one life.

Solstice Alignments

” Shakespeare saw the same stars in the same patterns that we do. So did Galileo, Columbus, Joan of Arc, Cleopatra and the first man-ape to look up in curiosity. From space age back to stone age, to be beneath the night is to witness something that every human who has ever lived has also seen. It is our common heritage.”

Stuart Clark, Beneath The Night, 2020.

The entrance to the stone lined chamber is on the south east side of the cairn. The chamber is fairly small, 3m by 0.6m, coffin shaped and just big enough to lie down in if you are brave and feeling flexible. It was here after the fire in 1984, during an excavation carried out by Charles Thomas on behalf of the Institute of Cornish Studies, that small deposits of cremated bone were found along with sherds of pottery thought to be from three different vessels. These bones fragments were radio-carbon dated giving us a date for interment of between 1690 and 1500BC.

It has never been, and may never be, clear whether these structures were simply tombs to contain the cremated remains of the dead or whether they served some ritual purpose or even had additional functions as boundary markers, something I discussed in my post on Chun Quoit. But at Bosiliack it is the position of the chamber, the direction that it faces, which has led to an interesting discussion on the motivations behind such burial sites. The cairn here faces the winter solstice sunrise.

  • bosiliack
  • bosiliack

Our relationship with the sun, moon and stars is, of course, timeless. In fact, in the 1970s Alexander Marshack already believed that incised marks on the Bilzingsleben Bone offered tantalising evidence that Paleolithic people were keeping track of the movements of the night sky perhaps as much as forty thousand years ago. And many prehistoric megaliths, tombs and circles seem to hint (and sometimes shout) at that connection.

“The relationship between the sun and the earth is a deeply symbolic one. At this distance in time we cannot be sure exactly how our ancestors viewed that relationship. Nevertheless it is significant that at megalithic tomb sites like Gavrinis in Brittany, Maes Howe on Orkney and the Boyne Valley in Ireland, the entrances to the burial chambers are aligned so that the sun enters only on a specific day of the year, such as the winter solstice, when the sun is reborn from the earth.”

Cheryl Straffon, Pagan Cornwall, 1993

Bosiliack has been referred to as Cornwall’s ‘mini-Newgange’ because of it’s comparable alignment to the famous Irish tomb’s orientation towards the mid-winter sunrise. In addition, Daniel, in his comprehensive guide on the chamber tombs of England and Wales, also suggests that there may be more to these sites than simply places to lay the dead to rest. He writes that the cremated deposits of human bones are seldom enough to have been complete cremations and proposes that they could have been more in the nature of ‘votive offerings’.

Bosiliack Settlement

In September 2011 a team of archaeologists led by Andy Jones undertook an excavation of the Bosiliack settlement. Since the fire in 1984 bracken has completely taken over the site and the investigation in part aimed to determine the damage that the plants were doing to the archaeology.


The Bosiliack village has twelve hut circles and is considered one of the largest and best preserved in the Penwith. The excavation uncovered pottery from around 2000BC as well as flints, possible hand tools and signs of later activity right into the Iron Age, so the area was occupied for many generations.

Maybe they stayed because of the free fruit in the middle of winter . . . ?!

“Ripe blackberries, —plump, juicy, and well-flavoured, —have been picked Bosiliack within the past few days.”

18th January 1883, Cornishman newspaper

Final Thoughts

The idea of solar and stellar alignments is a subject very much up for debate amongst archaeologists and prehistory experts. My personal opinion is that there are far too many examples of these orientations for it to be a complete coincidence. Add to this the inescapable importance of the natural environment to our ancient ancestors, a forceful, vital connection that even the most ‘in touch’ of us today would certainly struggle to comprehend, and it seems inevitable that they would honour that, mark it, in these monuments which they put so much of their limited resources into building.

“The need to celebrate the return of the longer days, as the seasons turn around at mid-winter, is compulsive. . .

Because of their reliance on the mid-points of winter and summer, on the start of spring which marks the time for planting seeds and the birth of animals, and on early autumn when plants ripen to harvest and young animals are large enough to be hunted, Stone Age hunters and early arable farmers divided the year, as we do, into four seasons.”

Shirley Toulson, The Winter Solstice, 1981

Many ancient sites in Cornwall are thought to have significant alignments. For example, the passages of our fogous, such as Halliggye, are thought to be designed so that the sun shines down them on certain important days of the year, and the stone circles often align with a solar event or constellation, Fernacre supposedly honours the mid-summer sunrise over Brown Willy as well as the Pole Star and the Great Bear.

Ultimately, we must be careful, all of this is conjecture and, as I have said many times before, we can never truly know or understand the motivations of these prehistoric builders, we can just marvel at their works and be thankful that these monuments have survived to amaze and ground us to this day.

So, perhaps the next time you pay a visit to one of the well known monuments that we are so lucky to have dotted around our landscape, you’ll keep your eyes peeled for the smaller, unamusing treasures nearby. which my opinion have just as much, if not more to offer.

Further Reading

Boskednan Stone Circle

Men Scryfa – Ravens & Cornwall’s first graffiti artist

Chun Quoit

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2 thoughts on “Bosiliack Chambered Cairn

  1. The winter solstice dawn alignment is quite something – about one year in seven when it’s clear enough to see it…I have a photo somewhere I’ll look out for you when I have a minute!

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