Offa's Dyke: Section extending 1960m from Yew Tree Farm to Quarries NE of Granner Wood

Cadw's description

Summary description and reason for designation

The following provides a general description of the scheduled ancient monument.

The monument includes the earthwork and buried remains of a section of the linear earthwork known as Offa's Dyke. Offa’s Dyke consists of a substantial bank and ditch extending, with some gaps, N-S through the border area between modern Wales and England from Treuddyn in Flintshire to Sedbury near Chepstow. The actual dyke only covers 132 km (82 miles) out of the total distance of 240 km (149 miles), the intervening gaps being filled by natural features such as slopes, valleys and rivers. The dyke generally consists of a bank, up to 3.5m high, with an intermittent parallel quarry-ditch on the western side giving a total width of up to 18 metres.

It is traditionally thought to have been built by the Mercian King Offa in the later 8th century, but may incorporate earlier earthworks. Whilst its exact function and original form are still the subject of debate Offa's Dyke is significant as the longest and one of the earliest surviving and long-lived territorial boundary monuments in Europe marking a nominal frontier between Saxon Mercia and Welsh kingdoms to the west. It represents one of the great engineering achievements of the pre-industrial age and the most dramatic built structure to survive from the early medieval (c410-1100) period in Britain. Offa's Dyke now survives in various states of preservation in the form of earthworks and, where sections have been levelled and infilled, as buried features. Although some sections of the dyke no longer survive visibly, sufficient evidence does exist for its position to be accurately identified for most of its length. Offa’s Dyke is scheduled in multiple different sections on both sides of the present border. These display their own local physical characteristics but all share and contribute to the overall significance of the monument and have potential to enhance our knowledge of the monument as a whole.

This scheduled section of the dyke is approximately 2.1 km long and runs from the B4356 450m W of Discoed southwards to the north side of Lower Dunns Plantation at SO 2745 6320. The remains included within the scheduled area vary in scale. The northern stretch of 800m consists of a substantial bank, standing up to c.3m high on its eastern side with the ditch 3m deep on its western side. In places along this northern section, there are traces of a counterscarp bank outside the western lip of the ditch. To the south of this, from SO 2697 6439, the dyke becomes much slighter although still clearly visible as an earthwork bank generally up to c.1m high, overlain for much of the length by later boundaries, with occasional slight traces of the ditch.

The monument is of national importance for its potential to enhance our knowledge of early medieval territorial organisation and settlement. The remains of the Dyke retain significant archaeological potential, with a high probability of the presence of archaeological features providing evidence of its construction use and decay, and deposits containing environmental and dating evidence. The upstanding earthworks are likely to seal pre-Dyke ground surfaces and soils which may provide evidence of the landscape and environment in which it was constructed. This section of the monument coincides with the Offa’s Dyke Path National Trail.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.