We’re very pleased to be able to bring you, in serialised form, a paper courtesy of Dr Euan MacKie regarding the Sheep Hill hillfort and associated rock carvings, which are currently under a long-running threat of destruction.

Quarrying may destroy two uniquely linked prehistoric sites of different eras

Summary

On the north bank of the Clyde a few miles west of Glasgow there are two scheduled prehistoric sites of considerable archaeological interest. Sheep Hill is a small two period hillfort on a prominent volcanic plug which is threatened with destruction by the local quarry; one of the finest cup-and ring carvings in Scotland used to be two hundred metres to its north but at the demand of the quarry the carvings were sawn off in 1994 and are now stored in the National Museums in Edinburgh. Historic Scotland allowed that to happen and is now prepared to let the hillfort go. In theory the carvings could be restored to their original site when the quarry’s licence expires. It seems that neither the local authority in West Dumbartonshire nor the Scottish Government is willing or able to pay the required compensation to the quarry company to save Sheep Hill. I carried out excavations on Sheep Hill in 1966-69 and recorded the rock carvings for Historic Scotland in 1984 and am convinced that not only are the sites worth saving in their own right but that they were actually connected in ancient times. It seems that when the first, timber-framed, stronghold was built in about 900 BC the nearby carved rock was quarried for building material, destroying many carvings; however the Neolithic tradition of cup-and-ring carvings was still alive locally and new ones were cut on to the freshly exposed surfaces, including a very fine double disc symbol. This hypothesis could be tested in any future excavations and if correct would make the two sites unique in Britain. The mere possibility of such a relationship means that Sheep Hill must be preserved.

Euan W. MacKie

Illus. 1: view of Sheep Hill fort – on the flat-topped summit in the centre – from the village of Old Kilpatrick, West Dunbartonshire. The scene shows how devastating to the environment the quarrying of the volcanic plug would be; the view of the Kilpatrick Hills from the south has remained unspoiled until now. Dumbarton Rock is just to the right of the church tower.

Illus. 1: view of Sheep Hill fort – on the flat-topped summit in the centre – from the village of Old Kilpatrick, West Dunbartonshire. The scene shows how devastating to the environment the quarrying of the volcanic plug would be; the view of the Kilpatrick Hills from the south has remained unspoiled until now. Dumbarton Rock is just to the right of the church tower.

Introduction

Sheep Hill is a two period hillfort situated on a volcanic plug of basalt on the Kilpatrick Hills north of the river Clyde in West Dunbartonshire, Central Scotland; it was partially excavated by the me in the late 1960s (1976). This conspicuous site (Illus. 1, above) overlooks the western end of the Antonine Wall at Old Kilpatrick – the northernmost frontier of Roman Britain which was built in about AD 140 under the emperor Antoninus Pius and functioned for about twenty years. The fact that neither of the two phases of Sheep Hill produced any Roman finds, despite the proximity of the Old Kilpatrick terminal fort, suggests that the hilltop was abandoned before the Romans established the frontier in about AD 80, using a line of forts more or less along the track of the later wall. The original fortification on Sheep Hill was a small dun with a timber-framed stone wall, enclosing a roughly oval area on the summit of about 40 by 43m; the stronghold came to a violent and fiery end when the timber -framed wall was burned. The consequent ‘vitrified fort’ was, according to the available radiocarbon dates, probably built in the 9th century BC and destroyed perhaps two centuries later.

The vast quantities of heated basalt fragments which were on the hilltop after the fire were later re-used to build a larger enclosure with earth and stone ramparts. The builders of Sheep Hill 2 made use of the natural terraces of the basalt summit to produce an enclosure containing several smaller enclosures; the central part of the hillfort seems to have been the summit of the hill, more or less the area enclosed by the earlier timber-framed wall. The southernmost rampart – together with a rubble stone pavement immediately north of it – was found to overlie a midden which had evidently accumulated downhill from the timberframed dun after it had been destroyed, this providing useful stratigraphical proof of the two distinct occupations. No signs were seen suggesting that the hillfort had been destroyed; it seems just to have been abandoned. Sheep Hill was scheduled as an ancient monument in 1970, and a summary account of the excavations was published a few years later (MacKie 1976, 211-14). The full excavation report will appear soon in the Scottish Archaeological Journal.

The Kilpatrick Hills slope steeply upwards from the Clyde and Sheep Hill is at the top of this slope (Illus. 1 & 7); immediately to the north however is a slightly lower area of flat ground, itself surrounded by slightly higher hills. In this natural amphitheatre was an outcrop with one of the most complex and spectacular cup-and-ring markings in southern Scotland, known as the Greenland (after a nearby farm) or the Auchentorlie (after a nearby house) cup-and-ring carvings (Morris 1981, 98-103). This may seem surprising in view of the prevailing basalt rock – highly unsuitable for carving – but the two groups of cup-andring marks are in fact on what are known as ‘rafts’ of sandstone which floated into their positions on rivers of lava in the eruptions of millions of years ago. The sandstone blocks of course were heated and hardened in the process and thus made more suitable for carving.

Illus. 2: high angle view of the main Greenland carved rock (no. 1) – a metamorphosed sandstone raft which was detached from its parent outcrop and floated to its present position by volcanic activity in Carboniferous times. It can be seen that the outcrop has been quarried in ancient times, presumably because the heat-hardened sandstone – which clearly breaks off into flat slabs – was useful for building. The old glaciated surface of the rock, bearing the more weathered carvings, occupies most of the rock next to the vertical edge at lower right. Pieces have clearly been hacked away on the left hand side (and probably also along all the lower edge), leaving flatter surfaces on which are the fresher, younger carvings. The most spectacular of these is the double disc symbol at top left which is shown in close-up in Illus. 3. Further damage to the rock was evidently done after this symbol was carved; part of one of the discs is missing at a step which defines an even lower area of rock on the left.

Illus. 2: high angle view of the main Greenland carved rock (no. 1) – a metamorphosed sandstone raft which was detached from its parent outcrop and floated to its present position by volcanic activity in Carboniferous times. It can be seen that the outcrop has been quarried in ancient times, presumably because the heat-hardened sandstone – which clearly breaks off into flat slabs – was useful for building. The old glaciated surface of the rock, bearing the more weathered carvings, occupies most of the rock next to the vertical edge at lower right. Pieces have clearly been hacked away on the left hand side (and probably also along all the lower edge), leaving flatter surfaces on which are the fresher, younger carvings. The most spectacular of these is the double disc symbol at top left which is shown in close-up in Illus. 3. Further damage to the rock was evidently done after this symbol was carved; part of one of the discs is missing at a step which defines an even lower area of rock on the left.

Unfortunately for the national archaeological heritage, in about 1972 the quarry firm Thompsons of Dumbarton acquired the Auchentorlie estate from its previous owner, Cdr. Alexander-Sinclair, presumably because of the availability of the hard volcanic rock. A few years later operations began just to the north of Sheep Hill and the owners eventually applied to Historic Scotland to remove the main carved outcrop as they wished to use the space for storage. This was agreed to and in 1984 I was asked to record the rock carvings (MacKie & Davis 1991). In 1994 the carvings were sawn off and the pieces taken for storage to the National Museums of Scotland in Edinburgh.

Now Messrs Thompson wish to quarry away Sheep Hill itself and Historic Scotland has also agreed to this in principle. I am trying to prevent this on the grounds that, if the Hill is preserved, then when the quarry’s license runs out in about 2040, it would be possible to restore the rock carvings to their original position close by, using either the originals or exact replicas of them, and thus to preserve an unique pair of sites. Their uniqueness is not just a matter of the propinquity of two radically different types of prehistoric monument just north of the Roman wall – although this alone should make them an interesting attraction for tourists if proper access was arranged – but because there might well have been a link between the two sites in ancient times which, if genuine, would make the pair the only one of its type in Britain.

Illus. 3. The two phases of carving on Greenland 1. The left view is of the double disc symbol with, on the right, one of the rock surface immediately to its right. The slight overlap between the pictures can be seen in the appearance in both of the rather rough cup-and ring mark immediately to the right of the double disc. The much fresher appearance of the double disc is apparent, as is the more weathered condition of the symbols to its right. Likewise the surface on which the double disc is carved is flat and has clearly been exposed by the splitting off of slabs; the more rounded and uneven glaciated original surface is clear on the right. Slight damage to the double disc was caused later, evidently by more slab removal 

Illus. 3. The two phases of carving on Greenland 1. The left view is of the double disc symbol with, on the right, one of the rock surface immediately to its right. The slight overlap between the pictures can be seen in the appearance in both of the rather rough cup-and ring mark immediately to the right of the double disc. The much fresher appearance of the double disc is apparent, as is the more weathered condition of the symbols to its right. Likewise the surface on which the double disc is carved is flat and has clearly been exposed by the splitting off of slabs; the more rounded and uneven glaciated original surface is clear on the right. Slight damage to the double disc was caused later, evidently by more slab removal

Next: The Greenland rock carvings