Offa's Dyke: Section N & S of Plas-Offa

Cadw's description

Summary description and reason for designation

The following provides a general description of the Scheduled Ancient Monument.

Offa’s Dyke is a boundary earthwork, believed to be of Early Medieval date running, with some gaps, for roughly 120km through the border area between modern Wales and England from Sedbury near Chepstow to Treuddyn in Flintshire. It is traditionally thought to have been built by the Mercian King Offa in the later 8th century, but recent excavations on a section near Chirk suggest that some sections 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 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 the Britain. 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. Approximately 80km of the monument coincides with the Offa’s Dyke Path National Trail, which runs from Prestatyn to Sedbury.

The monument is of national importance for its potential to enhance our knowledge of early medieval defensive organisation and settlement. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. A dyke may be part of a larger cluster of monuments and their importance can be further enhanced by their group value.

The scheduled area comprises the remains described and the areas around them within which related evidence may be expected to survive. The majority of the scheduled area is up to c.40m wide, forming a linear strip enclosing the bank and ditch.