Calanais: land of stone

The monument was not all built at the same time. The earliest element is the stone circle with its central stone, constructed around 2900 BC, during the Late Neolithic. The chambered cairn, and possibly also the rows and avenue, was then added around 2500 BC. Over time, and with climate change, the stones at Calanais became embedded in peat; it was only when this peat was cleared in 1857 that the magnificence of the monument was revealed. 

Before the monument was built, the area had been cultivated by farmers for several centuries. Farming was introduced to the Outer Hebrides around 3700 BC. People cleared the trees, grew wheat and barley and kept domesticated animals, predominately cattle and sheep. They crafted stone tools, including arrowheads and axes, and elaborately decorated pottery with incised designs.

They constructed  artificial islands  of timber and stone, known as crannogs, in many of the surrounding lochs and interred their dead in megalithic monuments, known as chambered cairns.

They travelled through the landscape and the seaways, and they developed and maintained connections with communities far beyond the Outer Hebrides – stretching from Ireland to Orkney. 

The monument today consists of five standing stones and two fallen stones ranging from 2 metres to 3.3 metres in height. The circle may originally have contained around 18 stones that formed a large circle nearly 20 metres in diameter. This is twice as big as the circle at Calanais I! The tallest stone appears to have been shaped into a distinctive point.  

In 1858, around one metre of peat was cleared away from the monument, revealing the full height of the stones. During this time four fallen stones were also found inside the circle along with an outlier to the east. This suggests a concentric circle. In addition, five small holes were also found inside the inner circle, each lined with smooth seashore pebbles along with fragments of charcoal.

Although some researchers have suggested the presence of an altar, hearth or well, others have suggested they were post-holes, perhaps used to support upright wooden stakes positioned inside the inner circle. In winter when vegetation is low, the post holes can still be seen as slight depressions in the ground.

Also found in the middle of the stone circle was a small cist and burial cairn (8.5m in diameter and 0.3m in height) which was probably inserted during the Early Bronze Age – a time when there was also burial activity at Calanais I.

Cnoc Fillibhir Bheag was formed of two concentric circles of stone. The outer ring is around 13m in diameter and consists of 8 standing and 5 fallen stones measuring between 1.8m and 1m in height. The inner ring averages 8 metres in diameter, with 4 upright stones ranging between 1.3 metres and 2.1 metres in height.

The stones are held in place by small boulders placed around their base within the earth, and it is possible there were more stones originally. At least eight of them show signs of having been quarried. 

Engulfed in peat, this was a difficult site to understand until from 2003 to 2006 removed up to 1.2 metres of peat and soil, exposing the prostrate stones and underlying bedrock. This revealed two concentric circles with a large outer ring, around 22 metres in diameter, comprising 17 stones and a smaller inner ring of five stones. The height of the stones would have ranged from 1.4 metres to 3.8 metres. In addition, there were three outlying stones, one standing to the north of the circle and two to the south. These outliers would have formed a short avenue leading upslope from the south along the spine of the crag and tail formation. 

Little to no soil cover at the site in the Neolithic meant that erecting the stones was a challenge. The usual practice of digging a hole in the ground to support the base of the stones was not possible, so instead the monoliths were supported on top of the ground using mounds of packing stones. This made the stones highly unstable, and this probably led to their collapse soon after they were erected. Six stones broke as they hit the bedrock and remained prone as peat began to form at the site. In one instance, a falling monolith hit the base of another monolith, causing it to collapse with a domino effect.  

The single monolith is around 1.5 metres in height and the packing stones around its base are still visible. Many of the other stones of the circle were likely reused as lintels in nearby blackhouses. 

Geophysical survey around this monolith in 2018 showed 12 ‘anomalies’ that form an approximate circle (30 metres in diameter) around this stone. Such features are often associated with lightning strikes! The size and intensity of this geophysical magnetic signature also suggests multiple, repeated strikes. As these strikes are visible in the bedrock, they must have occurred before the formation of peat approximately 6000 years ago.  

A semicircle arrangement of monoliths is highly unusual, and various suggestions have been made to explain this configuration. Some have suggested that the remaining stones only represent half of the original circle with the missing stones having long since eroded into the sea. Others have suggested another unusual configuration in the form of a split stone circle that straddles this channel. Looking across Loch Barraglom to the left (north) of the new Great Bernera Bridge, you can see a single standing stone within a sheepfold.

The stone was moved when the road was widened and has since been re-erected here. It is possible that additional stones existed alongside this one, forming the other ‘half’ of the split stone circle.  

Here, the position of the stone circle on a ‘crag and tail’ formation is clearly evident. From the road, the skylined stones are visible just to the north of the crag summit. At an elevation of 30 metres above sea level, the position of the stone circle forces an approach from the tail (or north), moving along the spine of the ridge for a dramatic arrival. Upon reaching the site itself, notice the commanding views this position affords in all directions except to the south, which is the opposite direction to Calanais.  

Although today much of the site is engulfed in peat, the spectacular visibility afforded by this location is still clear. From this site, the extensiveness of the whole Calanais landscape becomes apparent; circles I, II, III, IV, VI, X and XI are all visible from this location. Why so many monolithic monuments were built in the Calanais region remains a mystery, but investigations of many of these sites has led to a belief that the locations of the stone circles were just as important as the stone circles themselves. 

The position of this stone circle on the summit of a crag affords a high level of visibility over the landscape, particularly to the south and southeast, especially along the course of the Blackwater River. While the elevated route along the A858 affords great visibility, it also traverses a series of 'crag and tall' formations, which may have hindered prehistoric travel between the east and west coasts of Lewis. Hence, the lower lying land along the river to the south may have been preferable for movement either on foot or by watercraft.

These linear ridge formations are the result of glaciers running north-south across the landscape, carving out valleys and depositing glacial tills. When glaciers met rocky outcrops, they deposited glacial till in the characteristic ‘crag and tail’ formations seen across the landscape and often in association with these stone monuments.