The archaeological investigation focused on the recorded earthwork remains identified at Castrigg Roman Fortlet. The project comprised an archaeological trial trench evaluation, with three trenches located across the earthworks in order to provide information regarding form, function and development of the site. The trenches also tested the interpretation of a 2015 geophysical survey. The investigation involved the excavation of three linear trenches (T1-T3) measuring 30m by 1.8m. These sampled the visible earthworks and the geophysical anomalies identified during the 2015 survey, including several possible soil-filled features. T1 sampled the north side of the earthwork, which appeared well-preserved, while T2 sampled the possible annex on the southeast side. T2 sampled the two possible circular structures recorded by the geophysical survey inside the presumed enclosure. The purpose of the investigation was to obtain information on the date, quality, depth and state of preservation of potential archaeological remains and to date the period of occupation of the site. The fieldwork will be conducted by members of Appleby Archaeology Group and other project volunteers, with professional supervision and training provided by staff from Eden Heritage Ltd. The archaeological investigation confirmed the layout of the enclosure, with two sections excavated across the outer ditch. This had a U-shaped profile and showed evidence for erosion of the ditch sides, but no dating evidence was recovered from the fill. The ditch fill contained large quantities of cobbles and some large boulders, which may have been associated with an inner bank or wall, although this was not proven. Inside the enclosure, two ring ditches were revealed, which apparently related to two round houses or different phases, along with a possible wall foundation and a drip gulley. The ditches around the structures were probably necessary due to the boulder clay forming the hill, which was noted to be very poorly drained. Several post-holes and a pit were probably associated with the earliest round house (Round House 1), which appears to have been replaced with a slightly larger structure (Round House 2). No dating evidence was recovered from any of these features. Shallow pits were also identified within the enclosure but their date and function was unknown. A second outer enclosure ditch appeared to be part of an early field system. The upper fill of the ditch contained Romano-British pottery, suggesting it was filled in during the later Roman period. Radiocarbon dating was proposed to help date the occupation of the site.
Martin Railton (Wed,) studied this question.