Ogle Hill

Fort, Ogle Hill.

An oval fort occupying the summit of the spur and measuring 100ft by 66ft within a triple line of defences. The innermost defence has probably been a wall, while the other two, each of which has a ditch outside it, appear to be earthen ramparts. There are no internal features.

Visited by RCAHMS (KAS) 29 April 1956.

This fort is situated on the summit of Ogle Hill, which lies at the foot of the N spur of Coul Hill, and though it has been noted on three occasions, by David Christison (1900, 72, 73, fig 29), RCAHMS (in 1956) and the OS (in 1967), there is some doubt as to the exact composition of its defences. Nevertheless, it is oval on plan, and probably measures about 30m from E to W by 20m transversely (0.05) within the remains of a wall reduced to little more than a band of stony debris. In addition to this inner wall, there are up to two outer lines of defence, though whether these both encircle the whole summit is unclear. Where best-preserved, in the saddle on the E, they comprise earthen ramparts with external ditches, but on the flanks of the hill they are reduced to scarps. The position of the entrance is unknown and the interior has been obscured by trees since the mid 19th century, and though now in a clearing is partly encumbered by scrub and bracken. An evaluation trench was excavated across the defences in 2015 (Poller 2015).

Information from An Atlas of Hillforts of Great Britain and Ireland – 30 May 2016. Atlas of Hillforts SC2647

This small fort is situated on a spur (Ogle Hill) that projects from the NW end of Coul Hill, a rounded prominence that forms part of the Ochil Hill group but which is separated from the main massif by steep-sided stream gullies – that of the Pairney Burn to the NE and that of the Coul Burn to the SE. The spur is most easily approached from the SE, off near-level ground, but elsewhere there are steep, craggy slopes.

The innermost line of defence on the spur comprises a roughly egg-shaped enclosure, narrower at its SE end, which measures about 33m from NW to SE by 21m transversely within the grass-grown remains of a ruinous and probably heavily-robbed wall. By-and-large this wall has been reduced to little more than an uneven spread of rubble up to 7m in thickness, attaining an inner height of no more than 0.3m but with an external height of about 1.5m. Several areas of disturbance to this wall probably represent some form of early and undocumented investigation of the site. For instance, a narrow trench has been cut through the wall at the WNW end of the site and the top of the wall adjacent to it has been removed, leaving a roughly rectangular shallow depression. The interior of this enclosure is very uneven and no archaeological features could be discerned on the date of visit.

The second line of defence appears to have been another wall. On the SE, where it has blocked the easiest approach to the summit, it survives as a grass-grown bank measuring up to 5.5m in thickness by 0.6m high, and it is accompanied by a shallow external ditch, measuring about 4m in breadth, and the vestiges of an internal quarry scoop. Elsewhere on its circuit the wall has been reduced to little more than a spread of rubble with little or no discernible internal height but with an external scarp up to 1.5m high.

The third and outermost line of defence is roughly concentric with the second and its character is very similar, being reduced to little more that a stony scarp around most of its circuit but surviving as a grass-grown bank up to 6m in thickness and with an external height of 1.5m on the SE. A trench that has been cut through this bank, with the upcast thrown to either side, is probably further evidence of antiquarian investigation. The bank is accompanied by an external ditch that measures up to about 3.5m in breadth; at its N end this ditch peters out on the steep natural slope whilst on the south it swings round to the SW to continue into a poorly drained gully.

There is no dating evidence available for the fort. However, from the evidence provided by the survey, there is a good case for suggesting that the middle and outer lines of defence are contemporary. They are by-and-large concentric, both comprise a bank and an external ditch, and they are of similar scale. Without dismissing the possibility that these lines of defence were part of a structure that also included some form of summit enclosure, the proximity of the inner and middle walls on the NNE indicates that the summit enclosure that is visible today is probably later in date than the other defences. This conclusion is based solely on the assumption that it would have made no practical sense for two walls to have been built so close together.

In addition to the antiquarian investigations, the fort has been disturbed by quarrying which has removed portions of the middle and outer lines of defence on the W and NW. Further disturbance has been caused by the making of a track that approaches the summit from the W and descends on the ESE. This track is depicted on the 1st edition of the OS 25-inch map (Perthshire 1866, Sheet XCVIII.7), and it was part of a series of paths that provided a circuitous route to the summit starting and finishing at Cloanden (NN 9624 1158), the seat of the 19th century estate.

Visited by RCAHMS (JRS, GG, AMcC), 24 February 2015.

RCAHMS surveyed Ogle Hill fort between 23-24 February 2015 with plane-table and differential GPS at a scale of 1:500. The resultant plan and sections were redrawn in vector graphics software at a scale of 1:1000.

Partial excavation of this fort by Glasgow University in 2015 (Poller 2015) did not reveal any stratigraphic relationship between any of the lines of defence nor any evidence of contemporary buildings. Structural features of the defences included a slot at the front of the outer bank which probably held some form of timber revetment, and there is a suggestion that the ditch accompanying the middle wall/bank was re-cut. More significantly, the wall of the summit enclosure was shown to overlie a layer that was charcoal- and ash-rich, an indication of activity on the summit prior to the construction of the wall. The excavation also found structural remains of the 19th century summerhouse that is depicted at the NW end of the fort on the 1st edition of the OS 25-inch map (Perthshire 1866, Sheet XCVIII.7), and artefacts that pertained to its use.

Information from HES Survey and Recording (JRS) 15 August 2017.

NN 96940 11480 (Canmore ID: 26068, SMR: 3073) Resistivity survey.

Archive and report: National Record of the Historic Environment (NRHE) intended

Funder: Historic Scotland

Website: www.glasgow.ac.uk/serf

Tessa Poller and Cathy MacIver – University of Glasgow

(Source: DES, Volume16)

NN 96940 11480 (Canmore ID: 26068, SMR: 3073) Magnetometry survey.

Archive and report: National Record of the Historic Environment (NRHE) intended

Funder: Historic Scotland

Website: www.glasgow.ac.uk/serf

Tessa Poller and Cathy MacIver – University of Glasgow

(Source: DES, Volume16)

NN 96940 11480 (Canmore ID: 26068, SMR: 3073) A geophysical survey and excavation were carried out, 4 March – 18 April 2015, at Ogle Hill as part of the SERF project. The geophysical survey employed both gradiometric and earth resistance techniques. The results revealed a large igneous dyke cutting across the S side of the hill. Outside this area, in the E and W, traces of the outer two ramparts were detected. Possible evidence for the outer face of the inner enclosure was recorded on the summit. A strong magnetic circular feature was detected in the NW end of the survey, on a terrace within the second rampart.

Following the survey, two trenches were excavated; one measuring 40 x 4m which stretched across the upstanding ramparts onto the summit, and the other measuring 6 x 5m which was positioned over the strong magnetic circular feature identified in the survey.

The excavation of the long trench showed the outer bank to be largely composed of earthen dumps with scant traces of a possible stone cap or face. A palisade trench was identified along the bottom of the front face of the rampart at the edge of the outer ditch. The middle bank was characterised by dumps of chipped stone. In between the outer and middle ramparts were bedrock-cut pits. The innermost bank, which followed the break of slope of the summit, was a low spread of stones. No clear faces were identified. Flat areas of stone, levelling the undulating bedrock, may represent the only remains of occupation surfaces. An earlier charcoal-rich pit was dug into during the construction of the inner bank.

The second trench explored what would turn out to be a Victorian summer house. Information about the house, which had been destroyed for some time, came from the landowner. The excavations revealed a rough circular stone platform with frequent iron nails. Occasional glass and pottery and other occupation debris were also recovered.

Archive and report: National Record of the Historic Environment (NRHE) intended

Funder: Historic Scotland

Website: www.glasgow.ac.uk/serf

Tessa Poller and Cathy MacIver – University of Glasgow

(Source: DES, Volume16)

Archaeological features were identified and mapped from airborne remote sensing sources, such as lidar, historic vertical aerial photographs, and 25cm orthophotographs.

Information from HES (OA) 12 May 2017