A detailed magnetometer survey was carried out by Archaeological Surveys Ltd over a single area near Letcombe Bassett in Oxfordshire. The survey aimed to cover an outstanding survey area, not previously completed due to poor ground conditions, for a proposed new Thames Water pipeline between Lark Hill reservoir and Childrey Warren Water Treatment Works. The previous survey revealed a complex of enclosures and pits on land immediately to the south west and which appeared likely to continue into the current survey area. The results show a continuation of the archaeology, with a series of rectilinear enclosures as well as triangular and more irregularly shaped enclosures. A group of at least 10 ring ditches, associated with clusters of internal and external pits, have also been located beyond the pipeline easement. The majority of the archaeological features lie to the north of the proposed pipeline easement; however, the route does extend through some of the rectilinear enclosures, and also a currently proposed compound is situated over the site of a small, square enclosure on the western edge of the survey area.