This paper presents a re-assessment of the date and constructional sequence of the Sanctuary, a later Neolithic timber and stone setting on Overton Hill, near Avebury. Previous interpretations involving elaborate phasing and a protracted chronology for the site are rejected. Instead, it is argued that the site represents a single or double phase monument, constructed around 2500 cal BC and associated with pottery of the Grooved Ware tradition. The character of the pre-monument activity, construction and use of the site is examined. Patterns of formal deposition, involving pottery, lithics and human bone, are recognized, and considered in the context of the site's architecture and the structured organization of space, access and movement.