Carn Glas Chambered Cairns, Inverness: An Update

by Jonathan Wordsworth

The following is an addendum to the previous Carn Glas blog post of July 2023.

Drone image of Carn Glas after clearance of gorse looking north to Inverness and Moray Firth ©AHickie

It took two more days of work in August to clear the remaining gorse scrub off the cairn to reveal the monument in its glory.  With funding from Historic Environment Scotland we were able to get contractors to shred much of the cut waste, though a substantial amount of gorse remains outside the cairn on the east side.

We were fortunate to get Andy Hickie to fly his drone over the cleaned monument and as the photo above shows, this highlights the prominent position of the cairn overlooking the Moray Firth and with views to the hills north of the Great Glen and south to the Monadhliaths. This view is largely obscured by modern conifer plantations today but it now shows the significance of the monument’s siting in Neolithic times. No new details on the construction of cairns were visible on the ground in addition to that previously recorded by Henshall and Ritchie, but skilled processing of his aerial images by Andy Hickie has revealed the profile of this monument. (See also the recent Current Archaeology article on Carn Glas, featuring Jonathan’s text and Andy’s images. A transcription of the text from Henshall & Ritchie can be downloaded here).

Inked screenshot looking north with a profile of the topography on the southernmost cairn ©Andy Hickie

Carn Glas Chambered Cairns and Essich Farm, Inverness: An Interim Report

by Jonathan Wordsworth

The gorse covered mounds of Carn Glas on the skyline looking south west with a ploughed out roundhouse site in the foreground.

Background

In early march NOSAS members helped clear part of the gorse scrub encroaching onto the major Neolithic Cairn Carn Glas (Grey Cairn NH 6493 3830) sited on Essich Farm in Stratherrick above Inverness.  Sitting on a shallow saddle-shaped ridge on Essich Moor and overlooking the Moray Firth to east, the three interlinked cairns that form this monument make this, at 116 metres, the longest in the Highlands. Though now obscured by a modern forestry plantation, it is in a commanding position looking down the Moray Firth. For comparison the better known and partially reconstructed Camster Long Cairn in Caithness, itself comprising two round cairns, measures just under 70 metres in length.  This relative scale of the two cairns can be seen in the plans below drawn for Audrey Henshall’s Chambered Cairns of Scotland, where Camster is the second and Carn Glas the fourth image.

History of the site

The cairn lies on farm of Essich, one of the major tacks or holdings of the Mackintosh family with references to the land at least back to the 16^th century. 

The cairns at Carn Glas have been heavily robbed and the chambers emptied, probably as a source for stone dykes and other agricultural improvements dating to the late 18^th and early 19^th centuries.  V Gordon Childe in 1943 suggested stones may have been taken from here to build the section of the Military Road (built from 1725) that lies to the west and runs towards Loch Ashie.

The first known mention of the cairn itself is on a sketch plan of the farm by an unknown surveyor dating to 1834. Forming part of the muniments of the Mackintosh of Mackintosh family, it is stored with other documents dealing with Essich in the National Archives in Edinburgh.

Crown copyright. Papers of the Family of Mackintosh of Mackintosh, National Records of Scotland, RHP2187

The surveyor has probably (the text and image here are a little obscure) described the site as:

Glaischcairnmore so-called

a collection of stones on the summit of three hillocks

He has also shown three separate cairns, the easternmost and still most prominent today, is labelled Cairn. There is a suggestion of four stones ringing the middle cairn but other details are obscure. However it does seem the site had already been heavily robbed by this time.  The wider plan shows the boundary of the farm defined by a row of boundary stones some of which still survive today and date to 1794 suggesting this was a time of major works on the farm when stones for dykes and buildings might be needed.

Barrow-Loads of Barrows: Excavating a Monumental Pictish Cemetery at Tarradale on the Black Isle

by Eric Grant

Drone aerial photo showing barrows of different sizes and shapes (Drone photo: Andy Hickie)

In the first three weeks of September 2019 volunteers from the North of Scotland Archaeological Society supported by members of the local community excavated a suspected Pictish cemetery in a field near Tarradale House. Aerial photographs had previously shown the possible existence of a number of barrow graves in the area but there was little to see on the surface as the mounds had been almost totally ploughed away but their surrounding ditches appeared as ghostly outlines on the aerial photographs. A small, but growing, number of barrow cemeteries has been identified in Scotland but only a few excavated. Aerial photographs show the remains of at least 28 square and round barrows at Tarradale making it currently the second largest burial ground of this type in Scotland. The site could originally have been more extensive as parts of it have either been ploughed out or are too deeply buried to show in aerial photographs. Recent high-resolution photographs taken by drone have suggested the existence of more barrows towards the perimeter of the field and possibly into an adjacent field. Our excavations showed that Tarradale was a barrow cemetery of monumental proportions and potentially one of the most important in Scotland.

Although we are still waiting for radiocarbon dates from the Tarradale excavation, the presence of round and square barrows and their spacing and distribution leaves little doubt that we are dealing with a Pictish cemetery potentially from the 5th or 6th century AD, an important period in the formation of early kingdoms in northern Britain. Tarradale lies in the eastern side of Ross-shire on the Beauly Firth and only six miles from Craig Phadrig, an important stronghold and regional capital in the Kingdom of Fortriu. Part of this centralisation of power was reflected in the creation of monumental cemeteries and Tarradale may have been the burial place of the local elite. No Pictish symbol stones have been found at Tarradale, although symbol stones, including cross slabs with symbols on them have been found in adjacent parishes, the nearest being the recently discovered Conan stone three miles from Tarradale. However, in the same field as the barrow cemetery, a fortified settlement was excavated in the 1990’s; no primary dating evidence for the Picts was obtained but on stylistic grounds pottery from the fortified site has been dated to between AD 300-800 so this may well be the settlement focus of some of the people buried nearby.

Plan of barrow cemetery trenches (plan by Steve Birch)

Circles on the Photographs – Cataloguing the J S Bone Collection of Aerial Photography

by Jonathan Wordsworth

As part of the cataloguing the JSBone aerial photographs (see earlier blog post) donated to North of Scotland Archaeological Society, a team of NoSAS members have been identifying the sites revealed on these images.  Occasionally some intriguing queries arise. One such site came up recently and was from a photograph taken near Braelangwell on the Black Isle.  Here on an image from 2012, a series of small circular mounds were revealed.  Initial thoughts were that these might be the remains of an unknown barrow cemetery similar to that excavated at Tarradale.  While the density and similar size of the circles did cause some scepticism on their origin, searching on earlier Google Earth satellite views showed similar features were visible at least as far back as 2004.

JSBone P100014  Centred at NH68652 64114 and taken on the 14th January 2012. The low mounds highlighted by the winter sunlight are glacial moraines but in the field below are an intriguing set of circular and possibly square barrows.

Andy Hickie of Avoch Heritage was sufficiently intrigued by these, as he had previously identified a site of interest nearby the year before, that he agreed to fly his drone over these features, before processing to enhance the images through RTF software.  His results can be seen below.

Images processed by Andy Hickie from his drone photographs and which he describes as ‘photogrammerty-derived false colour images’.

Droning on about Tarradale

by Andy Hickie

Drone image of Tarradale Through Time barrow cemetery dig, as featured in “Current Archaeology” November 2019.

Back in 2017, I caved in to the demands of consumerism, and purchased a new quadcopter, a Phantom 3 Advanced, which is equipped with a camera and GPS unit. I flew multiple flights around Avoch but, after a while, the novelty of seeing one’s house from the air at different angles and altitudes begins to wear thin, and I began to wonder what I could actually do with a drone. Having always had an interest in archaeology and, spurred on by seeing some of the images Alan Thompson of NOSAS had created, I decided to carry out a few experiments of my own.

My first flights took in locations such as the distillery and settlement at Mulchaich, and the features of Kinbeachie castle – sites which had already been mapped by Alan by drone, the results of which I could use as a ‘benchmark’ against which I could compare those of my own.

At the same time, I began experimenting with various flight planning apps which allow for off-line autonomous flight planning, as well as online platforms for image processing. I found that “DroneDeploy” and “Mapsmadeasy” combined provided a fairly user-friendly pipeline, whereby image capture and photogrammetry can produce georeferenced photomosaics and digital surface models (DSMs). These can then be imported into software such as QGIS for further processing.

Having found the software which satisfied my needs, I then turned my attention to potential sites which I could map – and decided on the cropmarks of the Barrow Cemetery at Tarradale. At this point, my intent was purely to satisfy my own curiosity – just to see what I could see, and how it would compare with the archaeology found at the forthcoming 2019 dig.

And so, on 10 June 2018, accompanied by my daughter Emma to act as co-pilot and “spotter”, I visisted Tarradale to map the area with the drone. I can still recall the excitement I felt as the images began to appear on the monitor of the remote controller, which showed the cropmarks were developing. However, my satisfaction was tempered somewhat when I got home and began to process the photographs. Although the cropmarks were indeed evolving, the crop was insufficiently ripe, and many of the details remained hidden (see image below).

A Year of Highland Archaeology

by James McComas (NOSAS)

A Year of Highland Archaeology book cover, showing Tarradale Through Time excavation trench with the settings of a possible stone hut. The same trench yielded several rare antler tools.

NOSAS has just published A Year of Highland Archaeology: A Collection of the Projects and Activities of the North of Scotland Archaeological Society . This new book includes 10 articles which explore some of the diverse recent projects that we has been involved with. These range from large scale funded excavations through to group surveys and small scale research projects. They highlight Highland locations from the west to the east coast, from Speyside to Sutherland.

Projects featured include the lottery funded Tarradale Through Time Project, which in 2017 saw 6000 year old antler tools uncovered near Muir of Ord on the Black Isle.  These very rare finds included the remains of a harpoon point and two “T axes” left behind by hunter gatherers on the shores of the Beauly Firth. The T axes are two of only five examples so far known in the whole of Scotland. The trench where these were found also tantalisingly revealed the possible stone setting of a Mesolithic hut. Tarradale Through Time continues in Autumn 2019 with the excavation of potentially one of the largest barrow cemeteries in Scotland (further information at www.tarradalethroughtime.co.uk).

One of rare antler “T axes” found during Tarradale Through Time’s 2017 excavations.

Another chapter focuses on Torvean Hillfort, a neglected structure on the edge of Inverness. Torvean was perhaps constructed more than 2000 years ago, but it is today sadly under threat from persistent trail bike damage. A different chapter tells the much more positive story of how a collection of 400 historic maps relating to the Lovat Highland Estates, covering extensive areas west of Inverness, have now been scanned and made available online.

Map of Torvean Hillfort, Inverness showing destructive trail bike tracks

A different chapter still focuses on the NOSAS’s work with Scotland’s Rock Art Project. ScRAP aims to log as many as possible of the mysterious carved “cup marks” which appear on Scotland’s boulders and rock faces over a 5 year project. The precise date of these carvings, of which there are many good examples in the Highlands, is unknown but they are thought to have been mainly created in the Neolithic period around 6,000 to 4,000 years ago. Other archaeological locations explored in the book include Ormond Castle in Avoch, a prehistoric roundhouse landscape in Glen Urquhart, and Gruinard Island in Wester Ross.

3D Photogrammetry model of cup marked stone at Kinmylies, Inverness

Buntait, Glenurquhart: A Bronze Age Landscape?

by James McComas (NOSAS)

The larger barrow at Buntait – feature ‘X’ on the map below.

Although I have lived in Glen Urquhart for some years, it was only comparatively recently that I first visited Buntait, a hamlet just to the north of the Clava type chambered cairn at Corrimony. This was despite me hearing from a number of local people about the amount of upstanding archaeology that was there. I think I must have presumed that because there are no scheduled monuments there it could not be that interesting – an assumption I will not be making in the future. Later research confirmed that Buntait is in fact full of prehistoric (and post medieval) features – including hut circles, field systems, burnt mounds and rock art. Not only are the field systems extensive and some of the hut circles very well preserved, but also there are a couple of ditched barrow features. Locally, only Garbeg is comparable in terms of prehistoric remains.

GIS map of Buntait annotated with huts, barrows, cairn fields, dykes and other archaeological features.

Consequently Buntait became the subject of three archaeological field trips in 2017; two led by NOSAS, and one as part of the Archaeology Scotland Summer School planned with the assistance of NOSAS. There were also numerous smaller sorties for quadcopter flying, polecam photogrammetry, rock art recording (for SCRAP) and general investigation.

NOSAS field visit to Buntait January 2017

“The Glenurqhuart Story” by Alistair Mackell published in 1982, provides a useful if perhaps now outdated introduction:

Not far from the Corrimony Burial Cairn, on Buntait lands, was a settlement of some considerable size where clearly marked hut circles and cairns suggest a community practising primitive agriculture and a boundary wall, which can still be traced, may have served to protect domestic animals from prowling wolves or other marauding wild animals. Some of these circles are 30 feet in diameter and in the centre of at least one, is a depression which may have been a fireplace. These circles are low banks of stones covered with grass or heather about 2 feet high and 4 feet wide at the base. It is difficult to imagine one large roof covering such an expanse, but if so, it would probably have been formed of wattles and thatched with heather or turf, giving, when complete, a dome – shaped appearance. In each case there is a break in the circle at the south east which indicates the entrance. In other parts of Scotland where these structures have been carefully examined, hearth paving stones have been discovered, but we are unable to reconstruct much of the everyday life of the people of these long bygone days, and we can merely conjecture that they combined hunting with their primitive agriculture, for the Highlands were rich in wildlife.

Experiments using a Quadcopter for Archaeological Aerial Photography

by Alan Thompson (NOSAS)

Introduction

I’ve had my Quadcopter for over a year now, had great fun flying it, and have produced many interesting images.  I recently showed a selection of images at a NOSAS evening, and was asked if I would write this blog and share some of the things I’ve learned along the way.

Of course the pictures are what it’s all about and even if you’re not interested in my comments, I hope you enjoy looking at them.

Background

Inspired by some of the wonderful aerial photos (APs) I’ve seen (for example on Canmore) I have long thought how good it would be to be able to take such pictures of our own archaeological sites.

For several years I have been interested in photogrammetry and experimented with that, especially of rock art where the production of a 3D surface and use of computer generated lighting and shadows can give some great effects.

In 2013 I began to investigate kite aerial photography (KAP) but the possibility of using a Quadcopter also emerged and I realised that technology and prices were moving so quickly that it might be a better option.  In early 2014 I decided that the only way to learn was to buy one.

The Quadcopter – getting ready to fly

Most amateur Quadcopters are sold with very wide angle cameras, with the intention of video recording, and also providing a pilot’s view (called first person view or FPV).  This is less than satisfactory for archaeological aerial photography, and so I bought a Quadcopter without a camera, with a view to fitting my own.

The camera is obviously critical, and it needed to be light (ideally <300g including battery), robust, of good enough quality, and with an interval timer.  Unfortunately I could find no such camera.  All those with interval timers are heavier, for example those used for kite aerial photography.  A solution can however be found in that a group of people spend their time hacking the software of Canon cameras (google CHDK) and provide a hacked version for some models which enables an interval timer to be run.

Having bought and hacked my camera and got the interval timer working I had to fit it to the Quadcopter.  The main problem is the high frequency vibration from the rotors which renders the pictures useless.  A suitable anti-vibration mounting was needed, all within the weight limit.

Next, to prepare for the first test flight.  The web (YouTube) is full of videos of alarming crashes and fly-aways.  The Quadcopter instructions are daunting saying that a first flight should be from the middle of a large field, with no wind and no people about.  There is also the matter of insurance (it could certainly hurt someone badly), and the possible need for a CAA licence.  The regulations here are changing quickly but at present as a hobby flier I can insure through the British Model Flying Association (BMFA), and (unlike a professional archaeologist) have no need of a CAA licence provided I fly within line of sight, avoid certain areas (eg near airports) and limit the height.  I would again emphasise that this is all very much in the news and changing and my observations here will quickly be out of date.

The first flight is bit nerve-racking, but set to auto mode the Quadcopter uses its own GPS and compass and is set so that (more or less) if you let go of the controls it just hovers where it is.  Flying in this mode is reasonably straightforward.  I have not dared try any of the advanced modes as yet.