Wayland's Smithy in the context of "Ashbury, Oxfordshire"

Long barrows are a style of monument constructed across Western Europe in the fifth and fourth millennia BCE, during the Early Neolithic period. Typically constructed from earth and either timber or stone, those using the latter material represent the oldest widespread tradition of stone construction in the world. Around 40,000 long barrows survive today.

The structures have a long earthen tumulus, or "barrow", that is flanked on two sides with linear ditches. These typically stretch for between 20 and 70 metres in length, although some exceptional examples are either longer or shorter than this. Some examples have a timber or stone chamber in one end of the tumulus. These monuments often contained human remains interred within their chambers, and as a result, are often interpreted as tombs, although there are some examples where this appears not to be the case. The choice of timber or stone may have arisen from the availability of local materials rather than cultural differences. Those that contained chambers inside of them are often termed chambered long barrows while those which lack chambers are instead called unchambered long barrows or earthen long barrows.

The Cotswold-Severn Group are a series of long barrows erected in an area of western Britain during the Early Neolithic. Around 200 known examples of long barrows are known from the Cotswold-Severn region, although an unknown number of others were likely destroyed prior to being recorded.