A Springfield style enclosure is a roughly circular hilltop or spur enclosure bounded by a defensive circuit of ramparts and dating to the Middle/Later Bronze Age. They are named after the type site of Springfield itself (Buckley & Hedges 1987). They are generally characterised by a single ditch (although examples with double ditches are known) and a simple internal bank or box rampart. Sites in this class are relatively small in scale, all examples being under 1ha in extent, and many covering an area of approximately 0.25ha. Sites in this class have generally been recognised on the basis of aerial photography, although examples may also be recognised during the excavation of later sites which occasionally overlie them.
Due to their morphology and location, Springfield enclosures bear a number of similarities to other classes of site. They can be distinguished from ring ditches and Rams Hill style enclosures on the basis of scale, being larger than the former and significantly smaller than the latter, although a number of features are shared. Such sites should also be distinguished from early hillforts, both on the grounds of chronology and morphology. Sites in this class may also be confused with henges, although here again, they can be distinguished on the grounds of chronology and layout.
Patterns of association with other classes of site, together with artefactual material recovered during excavations, suggests that springfield enclosures played a largely domestic role, as settlements within a broader managed landscape between the 10th and 8th centuries bc. Evidence from excavated sites (eg. Mucking) suggests that the life span of individual examples may have been characterised by more than one phase of use. However, there is little to suggest any break in occupation between the different phases, which are generally characterised by the recutting of ditches and the cutting of additional internal features.