The construction of a natural gas pipeline across southern Wales and into Herefordshire and Gloucestershire between 2005 and 2007 resulted in numerous archaeological discoveries, including sites of national significance. The project not only produced a wealth of new archaeological sites, it also generated important radiocarbon and environmental datasets for the region.

The earliest activity is indicated by worked flint of Mesolithic (or earlier) date, with the earliest Neolithic communities represented by pits, evidence for occasional timber houses, and the discovery of a previously unknown henge. Beaker and Bronze Age settlement and burial remains were found too, including a rare copper halberd. The excavations also produced evidence for Early Bronze Age houses and numerous examples of burnt mounds.

Other discoveries comprised much new evidence for Iron Age settlement (including some in areas of upland), Roman roads, crop-processing ovens, and ironworking. Rare evidence for the early medieval period was also found, along with the remains of later farmsteads and field systems. Moves towards industrialisation were reflected in the discovery of a brick kiln and charcoal-burning platforms.