Downton can trace its ancient inhabitants to the Neolithic, Iron Age, Roman and Saxon times. Evidence of Neolithic occupation was found at Downton in 1956–7 during archaeological excavations in advance of a housing development. Close to this site, in 1953 the site of a Roman villa was discovered. Excavations in 1955-6 revealed a villa with tessellated floors, at least two featuring mosaics, a hypocaust and bath house. Roman features were found over an area of about 12 acres. The villa is no longer visible, but the finds, including one of the mosaics, are displayed in Salisbury Museum. Clearbury Ring, on high ground in the northwest of the parish, is an Iron Age hillfort.