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Offa's Dyke: Chirk Castle Section is an early medieval linear earthwork extending north-eastward from Castle Mill in Wales. Constructed probably during the late eighth century as a territorial boundary, the dyke represents one of the most ambitious engineering projects of Anglo-Saxon Britain. This section lies on Dinantian limestone and associated rocks of Mississippian age, which would have presented considerable challenges to the labour gangs constructing the bank and ditch. The underlying geology of mixed limestone, sandstone and argillaceous strata creates varied soil conditions across the route, affecting both the original construction method and the modern preservation of the earthwork's profile.
The monument is protected by Cadw under reference DE134. The section near Castle Mill survives as a substantial linear bank with an accompanying ditch, though the limestone bedrock has caused differential erosion and weathering along its length. The dyke's presence in this landscape marks the historic division between Welsh and English territories, with the fortification of nearby Chirk Castle many centuries later representing a subsequent phase of border control and military significance in the same strategic location.
Offa's Dyke: Chirk Castle Section extending NE from Castle Mill is a scheduled monument protected by Cadw under reference DE134. View the official record →
Offa's Dyke: Chirk Castle Section is an early medieval linear earthwork extending north-eastward from Castle Mill in Wales. It is designated a Scheduled Ancient Monument by Cadw under reference DE134.
Offa's Dyke: Chirk Castle Section extending NE from Castle Mill dates from the early medieval period, and is classified as a linear earthwork. It is one of over 32,000 scheduled monuments protected across the UK.
Offa's Dyke: Chirk Castle Section extending NE from Castle Mill is a Scheduled Ancient Monument, legally protected by Cadw — the body responsible for designating and safeguarding heritage sites in Wales. The official designation reference is DE134.
Several scheduled monuments lie within 10 km, including Castell Brogyntyn ringwork castle 300m north east of Brogyntyn Farm (6.5 km), Offa's Dyke: section 410m long, E of Llawnt (6.8 km), Offa's Dyke: section 400yds (370m) long, E of Llawnt (7.2 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Offa's Dyke: Chirk Castle Section extending NE from Castle Mill's history, each drawn from the record and mapped to the exact spot:
Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.
Offa's Dyke: Chirk Castle Section extending NE from Castle Mill stands on Dinantian Rocks (Undifferentiated), bedrock that formed in the Mississippian. The rock here is limestone with subordinate sandstone and argillaceous rocks.