Note
Date February 2017
Event ID 1038182
Category Descriptive Accounts
Type Note
Permalink http://canmore.org.uk/event/1038182
Archaeological importance
The stone circle of Na Clachan Aoraidh – the ‘Stones of Worship’ – is set high on the limestone ridge of Cnoc na Craoibhe above Loch Tummel. The site is an unusual ‘four poster’ stone circle – a square arrangement of four large stones on a low stone-built circular platform. It is an early Bronze Age site and was probably built about 4000 years ago.
Writing of Na Clachan Aoraidh in 1908, the archaeologist Fred Coles noted that the “site, scenery, megalithic remains and surroundings all combine to render the investigation of this group especially interesting”. It is a place with real character, with spectacular views over the surrounding landscape and towards Schielhallion and Ben Vrackie. Although likely ceremonial, the few excavated examples often also display activities associated with funeral pyres and cremation burials. There is a particularly dense concentration of such sites in northern Perthshire, with examples scattered through the Tay, Earn and Tummel valleys.
In 2012, an archaeological measured survey was undertaken of Na Clachan Aoraidh by terrestrial laser scanning, providing an accurate baseline record of the site. This quickly proved to be very useful: in 2016, following an unauthorised bonfire, archaeologists were required to investigate the site further and record the damage. Particular care was taken to explore the soil itself, taking samples to compare heat-damaged deposits with undamaged areas and sieving the soil for microscopic flakes of charcoal and cremated bone. The centre of the site has now been protected under the turf with a sacrificial layer of gravel.
Na Clachan Aoraidh is a site of significant archaeological importance: it contains important buried archaeological deposits, it has great architectural character and it commands a distinct setting within the wider landscape. It is a worthy cover star of the new FCS Outdoor Archaeological Learning resource and a great example of the ‘power of place’, whereby a visit to an archaeological site can inspire discussion, learning, creativity and reflection.
Ecological importance
But it is also a site of significant ecological importance, as the open summit of the limestone ridge of Cnoc na Craoibhe comprises about 22 ha of upland calcareous grassland. This is a relatively rare and species-rich habitat and is one of the habitats identified within the category of ‘conservation action needed’ within the Scottish Biodiversity Strategy. Maintaining and achieving the good condition of significant existing open priority habitat is a key environmental objective on Scotland’s National Forest Estate.
Species-rich grasslands are early successional habitats. The main threat to this habitat is under-grazing, with low grazing levels or a lack of grazing resulting in the accumulation of vegetation litter and soil nutrients. Over time, this creates a rank species-poor sward made up of relatively common palatable tall herbs. Although these more fertile grasslands provide better grazing, they are more common and don’t support as many species of plants and insects. Grazing animals tend to eat the lusher plant species, allowing the finer plants and flowers to thrive; and, by doing so, prevent the nutrients from being recycled into the soil again. The more aggressive plants cannot invade and displace the rare plants which thrive in low nutrient conditions.
So grazing often has a vital role to play in improving, maintaining or enhancing significant open habitats and archaeological sites. The open summit of Cnoc na Craoibhe was fenced, the regenerating conifers were felled and removed and conservation grazing was introduced at this important upland calcareous grassland habitat. Including the conservation management (and condition monitoring) of the ‘four poster’ stone circle as part of the conservation grazing demonstrates Forestry Commission Scotland’s ecosystem approach to integrated land management.
Matthew Ritchie - Archaeologist, Forestry Commission Scotland
