The Cosener's House, 1516 Abbey Close, Abingdon, Oxfordshire

2 Methodology 2.2.1 The evaluation works involved the excavation of two trial trenches; each located to target the footprints of a proposed soak-away tank and manhole shown in Figure 2 Both trenches measured 3m by 1.6m. 2.2.2 The evaluation was designed to examine areas of impact identified from proposals which elsewhere indicate will adopt a no dig approach for the main car park area, which will be raised above ground level. 2.2.3 The trenches were laid out as shown in Figure 2 using a GPS with sub-15mm accuracy, except where minor adjustments were required owing to ground conditions or site obstructions such as a lamp post on the northwest corner of Trench 1. 2.2.4 The trenches were excavated using an appropriately powered mechanical excavator fitted with a toothless bucket under the direct supervision of an archaeologist. Spoil was stored adjacent to, but at a safe distance from the trench edges. 2.2.5 Machining continued in even spits down to the top of the undisturbed natural geology or the first archaeological horizon, depending upon which was encountered first. Once archaeological deposits were exposed, they were recorded by hand in line with the approved Written Scheme of Investigation (OA 2022). 2.2.6 The exposed surface was sufficiently clean to establish the presence/absence of archaeological remains. A sample of each feature or deposit type, for example pits, postholes, and ditches, was excavated and recorded where it was safe to do so. 2.2.7 Due to the limited access to the site, the type of machine was restricted to a minidigger and trenches could only be opened to a depth of 1m. An augur was used in both trenches to examine deposits to a depth of 1.3m. This was the proposed impact depths of the soak-away tank and manhole. 2.2.8 The watching brief was maintained during the groundworks associated with the construction of two new summerhouses within the gardens of Coseners House Hotel In June and November 2022, Oxford Archaeology was commissioned by the Science and Technology Facilities Council to undertake an archaeological watching brief on the site of two proposed summerhouses and two evaluation trenches in advance of drainage works relating to a proposed car park in the grounds of Coseners House Hotel, Abingdon. The site is situated within the precinct of Abingdon Abbey, a Scheduled Monument (1006309). The watching brief was maintained during the groundworks and the trenches located on areas of proposed drainage impacts. The watching brief identified no archaeological remains in the areas investigated. The existing turf on the site overlay 19th-20th century landscaping deposits containing modern debris. No significant archaeological remains or finds were identified other than modern material. The trenches identified the same landscaping layers seen in the watching brief, but extended down to greater depth, where a possible undisturbed occupation layer was encountered in Trench 1 at a depth of between 1.18 and 1.28m. The current drainage design shows the proposed impacts extending to a depth of 1.30m, which will place it at the interface with a potential archaeological horizon identified in Trench 1. Based on the current drainage designs further archaeological monitoring may be required during the construction phase of the proposed works.