In November 2018, Northern Archaeological Associates Ltd (NAA) was commissioned by Tees Archaeology to undertake a community-led geophysical survey to the south of the River Tees at Cliffe, North Yorkshire, as part of the HLF funded ‘River Tees Rediscovered’ project.

Cliffe is situated within an archaeologically rich landscape that contains vibrant evidence of human activity. The earliest includes several round barrows that date from the Late Neolithic to Early Bronze Age. One of these is located in the south of the survey area and is a Scheduled Monument, known locally as Betty Watson's Hill (Monument UID: 1016263). During the Roman period, a fort was built to the north of the site at Piercebridge and the standing remains of a Roman bridge spanning the River Tees were located directly to the east of the survey area. It is possible that further activity dated to the Roman period is extant to the south of the Tees, and it has been suggested that a Roman fort pre-dating the known one at Piercebridge was located on the plateau overlooking the southern banks of the river, possibly within the current study area.

In 2009, several areas in the hinterland of Piercebridge Roman Fort were targeted using geophysical survey and trial trenching by GSB Prospection and Wessex Archaeology as part of a Channel 4 Time Team episode. The results of these investigations located Dere Street Roman road running from north to south through the east of the survey area and identified a potential prehistoric or Roman enclosure that contained a roundhouse to the west of the Roman road.

Over two days, NAA was helped by the local community to evaluate the potential for previously unrecorded buried remains of prehistoric or Roman date to the south of the Tees across an area of approximately 4.6ha. Generally, anomalies detected by the geophysical survey complemented features identified on LiDAR and drone survey data, as well as those previously identified by the investigations undertaken in 2009. The results of the geophysical survey detected anomalies likely to relate to previously documented buried features dated to the prehistoric and Roman periods, as well as additional linear, rectilinear and curvilinear anomalies that, although tentative, could be indicative of previously unrecorded human activity. Medieval field systems also were clearly visible within the results of the geophysical survey and included three distinct alignments of ridge and furrow, as well as surrounding headlands.

Interpretation of the geophysical survey is achieved through the analysis of anomaly patterning, form and increases in magnetic response, and is often aided by examining supporting information (including, but not limited to, historic maps, LiDAR survey data, and aerial photographs). Luckily, the surveyed area at Cliffe was included in the Environment Agency’s LiDAR coverage, which gave a good general indication of the shape and form of the recent ground surface. Not only did this confirm the presence of the medieval “reverse S” ridge and furrow, along with associated headlands, but it also clearly demonstrated that the field system continued further to the north, beneath Kathleen Wood. The LiDAR also shows that the field systems respect the round barrow monument of Betty Watson’s Hill, indicating that it was a recognised feature in the landscape during the medieval period. As the resolution of the LiDAR is relatively low and doesn’t necessarily represent the current ground surface, it was decided to undertake a high-level drone photographic survey of the site. From this new survey, we were able to produce a much higher resolution 3D surface model using a technique called ‘Structure from Motion’. Draping the geophysical survey results over this model allowed us to gain a much clearer understanding of the relationships between the above and below ground features identified during the project.

Like the project at Eryholme, NAA’s team were able to demonstrate their passion for furthering the record of archaeological rich landscapes, as well as their ability to help train and mentor volunteers in the use of specialist non-intrusive archaeological survey methodologies. Several of the volunteers that participated in the fieldwork at Cliffe also helped NAA to collect the geophysics survey data at Eryholme, and so were able to further hone basic archaeological survey skills using magnetometer and GPS instruments. On both projects, working with the local community within the Tees Valley definitely made a day’s survey very enjoyable.

The Ancient Monuments and Archaeological Areas Act 1979 requires that a Section 42 licence must be acquired prior to any geophysical survey within a Scheduled Monument area. Therefore, a vital part of the pre-survey setup included securing a Section 42 licence and, following completion of the works, we were required to submit a final report with necessary questionnaires to Historic England. NAA worked with Tees Archaeology to ensure that the various stages of the license were completed with ease and the final report was submitted within the required timeframe.