Site Event/Activity record ECH6895 - Northgate Redevelopment, Phase 1, Grassy Knoll, Chester: Archaeological Strip, Map and Record Report

An archaeological Strip, Map and Record was undertaken in 2019 in the Grassy Knoll (also known as the ‘pocket park’) on the south side of Hunter Street, Chester (NGR: SJ 40312 66457), as part of Phase 1 of the proposed Chester Northgate redevelopment. In total, three trenches (Trenches A-C) were excavated, to determine the depth, below the modern surface, of the uppermost significant archaeological deposits, and to identify any areas where significant archaeology may have been damaged or destroyed. The purpose of this was to determine the potential impact, on significant archaeological remains, of proposed structural features in this area, such as pile caps and lift pits, the trenches being positioned to encompass the proposed locations of as many of these features as was practicable. The top of significant archaeology within the area of the Grassy Knoll was identified in all three trenches. For the most part, this comprised a seemingly extensive horizon of sandstone rubble, which almost certainly derives from buildings in the Roman legionary fortress, in this case probably barrack blocks within the central range. A fragment of sandstone walling, potentially forming part of one of these barracks, was also recorded in Trench A. These remains were buried beneath a considerable depth of later material, so that they mostly were approximately 1.7-2.5m below the modern surface across the area investigated. The significant archaeological remains were sealed by a thick build-up of dark soils that, from the associated finds, appear to have accumulated over a prolonged period, potentially (on stratigraphic grounds), from the early post-Roman period to the post-medieval period. This was cut by concrete foundations potentially relating to the nineteenth-century Ragged School that once stood on Princess Street, and is depicted on historical mapping. Subsequently, a considerable depth of material was deposited over the area in modern times, seemingly in relation to landscaping during the establishment of the Grassy Knoll. (1) Post excavation analysis for the full scheme of mitigation undertaken as part of the Phase 1 re-development. (2)