The Osborne Street borehole demonstrated the considerable thickness of archaeological deposits (4m deep) in this area, and also the moist, organic-rich soil conditions. The existing paving slabs and modern make-up were removed beforehand and the upper levels dug by hand to a depth of 1.2m. The borehole was drilled to a depth of 7m in 1m sections, and was 100mm in diameter. The arisings from the upper 2m of the borehole were not examined in detail. The arisings from the remaining five sections were laid out for inspection in polythene tubes. The 3-4m section was removed from the site for further sampling. Apart from modern make-up, the archaeological sequence consisted mainly of post-Roman topsoil or ‘dark earth’ (L1), 2.5m thick. Three fragments of peg-tile of late medieval/post-medieval date and a piece of animal bone were recovered from near the base of this layer. An environmental sample was taken from the bottom of this layer. The ‘dark earth’ probably consisted mainly of medieval and post-medieval topsoil and pits. Below the ‘dark earth’ was a well-defined peaty layer (L2), 0.42m thick. This contained much decayed vegetation, and it was sampled for pollen and for plant macrofossils. No finds were recovered from L2 and it remains undated. Some woody fragments were recovered from L2 and sent for a radiocarbon date. A medieval or Roman date seems the most likely. There were thin grey clayey deposits immediately above and below L2. These were possibly water-lain deposits. Two small undiagnostic brick/tile fragments were recovered from the upper clayey layer. An environmental sample was taken from the lower clayey layer (L3). Natural sand and gravel (L4) was reached at a depth of 4m. In pollen sample <3> (3.77m), pollen grains and spores are well-preserved and occur in high concentrations (thye were poor in the other two samples). The assemblage indicates that the dryland vegetation consisted of mixed deciduous woodland, dominated by lime, elm, oak and birch, with an understorey of hazel shrubs and grasses. The wetland vegetation comprised alder woodland, with an understorey of sedges and grasses. There is also unequivocal evidence for human activity, indicated by the presence of cereal pollen and suggesting localised cultivation. Plant macrofossils were scarce within the upper and lower deposits, but were moderately common within the organic mud (L2). In summary, the upper deposit (L1) would appear to be largely composed of burnt refuse, although the origin of this material is unclear. The central layer (L2) of organic mud appears to have accumulated within an area of derelict damp grassland or marsh. A low density of charcoal fragments is present but, otherwise, there is little evidence of human activity within the immediate area. Although the lower layer (L3) may have been infiltrated by some plant roots, it would otherwise appear to be little disturbed and may be part of the natural subsoil. The organic mud deposit (sample 2, L2) contained the highest density of plant macrofossils. Seeds of grassland herbs and ruderal weeds including hemlock (Conium maculatum), dead nettle (Lamium sp.), buttercup (Ranunculus sp.), mignonette (Reseda sp.) and stinging nettle (Urtica dioica) were recorded along with seeds/fruits of wetland plants including sedge (Carex sp.), marsh marigold (Caltha palustris) and rush (Juncus sp.). A test-pit (1.5m square) near the junction of Stanwell Street and Southway revealed a modern service trench and other obstructions at a depth of 0.5m. Due to the difficulties encountered on site, the excavation of the test-pit was discontinued. <1>