Evaluation and watching brief by D Score of OA as part of a programme of investigation in advance of and during the proposed redevelopment of part of the interior of the Scheduled Monument. Most of the area evaluated had been previously truncated and levelled, but two late medieval or early post-medieval ditches and an associated pit and gully, two large undated linear features (either ditches or possible former channels of the nearby river Wey), and two possible prehistoric ditches, were recorded. The watching brief revealed several curvilinear features with associated Mesolithic or Neolithic worked flints, although the majority of the observed features and deposits were probably of natural origin.