This paper presents data from a recently documented hilltop Buddhist complex called Mawasa, in the Raisen district of Madhya Pradesh, central India, about 15 km to the east of the UNESCO World Heritage site of Sanchi. It was documented during the Sanchi Survey Project, a multi-phase exercise aimed at relating the histories of Buddhist monasticism and urbanism as represented by the sequences at Sanchi and nearby Vidisha respectively to archaeological patterns within their hinterland. The dataset at Mawasa offers a well-preserved and representative sample of many of the main architectural types found at Phase II (c. 2nd - 1st century BC) Buddhist sites in the study area. It includes a well-preserved stūpa, a carved slab with an early and unusual Brahmi donative inscription, and a group of interesting platformed monasteries with well-preserved internal details. All of these provide important new insights into the nature of patronage and the history and chronology of Buddhist monasticism and monastery architecture during this early period of Buddhist propagation. Further, an enigmatic structure, the precise function of which remains unclear is located within the site. It may be a very early shrine of a hitherto unstudied form, and thus has potential relevance for the wider history of early temple architecture.