Details

The monument includes the earthwork and buried remains of a section of the
linear boundary known as Offa's Dyke 90m east of Ty Gwyn. Offa's Dyke
generally consists of a bank, up to 3.5m high, with an intermittent
parallel ditch and quarry pits in places. It was strengthened in some areas
by additional earthworks, namely a berm between the bank and ditch and a
counterscarp bank on the outer lip of the ditch.
In this section the Dyke runs for 740m from the road junction 350m north of
Ty Gwyn to the edge of the workings of Llynclys Quarry. At the northernmost
end of this section the Dyke has been reduced by the construction of the
road, but will survive as a buried feature. Beyond this, the Dyke runs
downslope and across the head of a small dry valley as far as Blodwel Bank
road. Here the Dyke is visible as a well-defined bank, up to 2.5m high, with
a ditch and a slight counterscarp bank in the central section. To the south
of Blowdel Bank road the Dyke is visible as a bank which takes the form of
a commanding scarp. In the garden of Bryn Offa, the ditch has become
infilled, but will survive as a buried feature and is included in the
scheduling.
In the southern part of this section, the Dyke changes its profile to take
account of the steep slope of the flank of the hill at this point. Here the
bank is up to 1m high on its eastern side. To the west, the bank falls away
steeply into the ditch, which has become largely infilled by landslip. A
pronounced counterscarp bank is visible to the west of the ditch. A series of
small quarry pits on the east of the bank provided further material for the
bank's construction. These are visible as a series of shallow hollows up to
10m from the base of the bank itself. The quarry pits have been partly
obscured by later ridge and furrow cultivation. Further sections of Offa's
Dyke 20m to the north and across the valley beyond the quarries at Llynclys
and the village of Porth-y-waen are the subject of separate schedulings.
All fence posts, telegraph poles, road surfaces, and the garden rockeries and
furniture of Bryn Offa are excluded from the scheduling, although the
ground beneath these features is included.

MAP EXTRACT
The site of the monument is shown on the attached map extract.

Source: Historic England

Reasons for Scheduling

Offa's Dyke is the longest linear earthwork in Britain, approximately 220km,
running from Treuddyn, near Mold, to Sedbury on the Severn estuary. It was
constructed towards the end of the eighth century AD by the Mercian king Offa,
and is believed to have formed a long-lived territorial, and possibly
defensive, boundary between the Saxon kingdom of Mercia and the Welsh
kingdoms.
The Dyke is not continuous and consists of a number of discrete lengths
separated by gaps of up to 23km. It is clear from the nature of certain
sections that differences in the scale and character of adjoining portions
were the result of separate gangs being employed on different lengths. Where
possible, natural topographic features such as slopes or rivers were utilised,
and the form of Offa's Dyke is therefore clearly related to the topography.
Along most of its length it consists of a bank with a ditch to the west.
Excavation has indicated that at least some lengths of the bank had a vertical
outer face of either laid stonework or turf revetment. The ditch generally
seems to have been used to provide most of the bank material, although there
is also evidence in some locations of shallow quarries. In places, a berm
divides the bank and ditch, and a counterscarp bank may be present on the lip
of the ditch.
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 frontier system no longer survive
visibly, sufficient evidence does exist for its position to be accurately
identified throughout most of its length. In view of its contribution towards
the study of early medieval territorial patterns, all sections of Offa's Dyke
exhibiting significant archaeological remains are considered worthy of
protection.

The section of Offa's Dyke 90m east of Ty Gwyn survives well and will retain
evidence of its construction and use over time, providing insight into the
technical skill of the people who built it.
In addition, environmental evidence in the form of pollen and seeds will
survive on the buried ground surface beneath the bank and in the ditch. This
evidence will provide information about the landscape in which the monument
was constructed.

Source: Historic England

Sources

Books and journals
Kay, K, Richards, , Offa's Dyke Path North, (1995), 18

Source: Historic England