THE PROBABLE ROMAN GASK SERIES TOWER AT WEST MAINS OF HUNTINGTOWER, PERTH
1997 Reconnaissance Excavation: Interim Report
D.J. Woolliscroft

The Site

The site of Huntingtower was discovered from the air by G.S.Maxwell in 1985 and has since been seen in a number of seasons, notably 1988 and 1992. It appears as a penannular ring ditch at NO 071247 with a single entrance break on its north-western side. The site stands at the crest of a steep ridge with superb views in all directions except the south, where the ground continues to rise, albeit much more gently. The immediate surroundings contain a significant concentration of sites of pre-historic date, notably the henges at North Blackruthven and Mains of Huntingtower (NO 068246 and NO 082251) and the large Huntingtower cairn or tumulus at NO 069249, but the site has been proposed as a Roman Gask series watchtower since its discovery. Its single entrance faces onto the likely course of the well known Huntingtower pit alignment (NO 072248 – NO 082250), which is thought to represent the course of the Roman road from the Gask Ridge to the fort of Bertha and the latter would have been in sight from the likely height of a Roman tower. There were, however, difficulties with such an interpretation, notably the size of the ditch crop mark. For this would suggest an external diameter of c.15m, which is 4-8m smaller than those of the other towers in the series.

Resistivity Survey

To obtain additional data on the site’s dimensions, morphology and exact location, a resistivity survey was conducted. The ring ditch and entrance break showed clearly on the resulting plotand, as on the air photographs, there seemed to be an additional weakening, but not a break, in the ditch opposite the entrance on the south-east side. The survey did, though, produce one surprise, for despite the fact that the site shows from the air as a positive crop mark, the ditch appeared as a series of high resistance readings, rather than as low readings, as is more usual. This phenomenon is far from unknown, however, especially on sites where the ditch backfill contains a significant quantity of stone.

The impression, gained from the air photograph, that the site is unusually small for a Roman tower was confirmed. The ditches of such towers usually fall into a size range of between 20 and 30m in external diameter, with the average being around 24m. To date the smallest known tower ditch on the Gask system (Westerton ) is 18.44m in diameter, which is itself between 2-6m smaller than the rest of the system’s towers, but Huntingtower is only c. 15.3m in diameter, which is very small indeed and smaller even than the inner ditches of some of the southernmost double ditched Gask towers (e.g. Blackhill Wood). The air photographic and geophysical data, thus left strong doubts as to whether the site could be a tower.

In addition to the main site, one 1992 air photograph shows what appears to be a second ring ditch, c.150m to the east of the first at NO 073247, just inside the eastern boundary of the same field. However, a second resistivity survey conducted here could detect no sign of buried features. This would suggest that the feature is very slight in nature, as would the fact that it has only ever shown once from the air, and the feature may even be an artefact caused by tractor activity.

The Excavation

In view of the doubts over the site’s identity, two trenches were dug as a reconnaissance, in advance of more extensive work planned for 1998, these being a ditch section and a small 2 x 2m area in the interior. The section revealed a “V” shaped ditch, exactly on the line of the dark circle marked on the resistivity plot. This proved to be 1m deep and around 2m wide, although an exact width could not be recorded since the ditch sides had been somewhat disturbed by two land drains: a modern pipe drain on the north-eastern side and an older rubble drain to the south-east. The ditch had silted to about half its full depth (L’7) and then been backfilled with loam (L’s 4-6). All of the fill material was very free draining, which would explain the odd resistivity results, since the material would tend to dry more readily than the natural red/orange clay into which it was dug and so present a higher electrical resistance.

Immediately outside the ditch a small gully was revealed, c.18cm deep and averaging 28cm wide. In plan the feature appeared to take the form of an arc, and contained a consistent fill of pale yellow turfy clay (L’2). No datable material was uncovered in connection with this gully and its date and function must thus remain unknown, but it may have formed part of some circular structure, such as a round house foundation. Sadly, the point at which the arc would have intercepted the ring ditch had been destroyed by the modern drain, but the gully could certainly not be picked up again cutting into the ditch fill on the other side of the drain slot and so the ditch is probably later (the modern drain is certainly so).

The small trench dug in the interior found nothing except for a small spread of turfy material in its northern corner. This might have been the edge of a post pit, but certainty must await the planned additional work.

No datable artefacts were uncovered in connection with the ring feature, but the ditch’s “V” profile is fully consistent with Roman military work, whilst its width and depth is comparable to those of other Gask System tower ditches. This means that the site may well still be a Roman tower, albeit one with an unusually small diameter and, if so, the size offers an intriguing possibility. There are already at least two, and possibly three, towers designs on the Gask and it could be that Huntingtower represents yet a fourth, especially since its nearest neighbour, Peel (so far known only as an air photographic target), also appears to be small. Confirmation of the site’s identity must obviously await the more extensive 1998 excavations but, in the meantime, it is hard to resist noting that most Roman military building was undertaken by the legions and that there were four legions in Britain at the time the system was built. It is possible, therefore, that the Gask was constructed in four building sections with one legion responsible for each, and that each legion produced a slightly different tower design. If so, a similar approach was taken later on both Hadrian’s Wall and the Antonine Wall, where again small variations in the installation types can be assigned to particular legions, and so such an arrangement on the earlier Gask line need occasion little surprise.