The Glamorgan-Gwent Archaeological
Trust Historic Environment Record
following information has been provided under the terms and conditions
of access as detailed on GGAT’s website www.ggat.org.uk.
Copyright is reserved on all data supplied by the GGAT HER Charitable Trust.
All output resulting from the use of the data must acknowledge the source
from information held by the GGAT HER Charitable Trust copyright.
data below is intended to be used for information and research only and
is not for use as part of a commercial project. If you wish to use
information derived from material held by the GGAT HER Charitable Trust
for publication in printed or multimedia form or to compile resources for
commercial use, prior permission must be obtained in writing. For further
information or to arrange a visit to the Trust please send an enquiry form
CLAWDD MAWR GLYNCORRWG
Primary Reference Number (PRN) : 02791.0w Trust : Glamorgan Gwent Community : Glyncorrwg Unitary authority : Neath Port Talbot NGR : SS8942894894 Site Type (preferred type first) : Early Medieval Dyke Status : Scheduled Monument
Summary : The dyke runs almost straight for 192m WNW to ESE. On the N. end, the bank and ditch measure about upper 7.5m by about 1m high overall, but the earthwork decreases in size towards the S. There is no sign of stonework.
Description : Clawdd Mawr, Bwlchgarw, the dyke runs almost straight for 192m WNW to ESE and is located roughly 15m above the floor of a narrow saddle running from Mynydd Caerau. The N. end lies at the head of a steep-sided natural gully, the S. on a steep slope. There is a gap were a track crosses it, but this appears recent. Near the N. end, the bank and ditch measure about upper 7.5m by about 1m high overall, but the earthwork steadily decrease in size towards the S. end, where it is now merely a shelf about 1.5m wide. There is no sign of stonework. On the three first edition OS maps (1877; 1899; 1918), another track can be seen, crossing the dyke on the southern half. The current one dosesn't appear in them.
Clawdd Mawr is a long dyke (c200m) composed of a bank and traces of flanking ditches. The dyke, which is also known as Bwlchgarw, sits astride a low saddle on the 470m OD contour between the mountains of Y Wernfa to the northeast and Mynydd Caerau to the southwest. The overall width of the dyke is c7.5m and is composed of a stone revetted earthwork bank c1m in height and shallow (c0.2m) ditch to the southwest. The dyke has been shown to have been cut into the natural northeast facing slope with an additional ditch and the stone revetment situated on the northeast side (Crampton 1966, 381). An investigation by Crampton (1966, 380-82) has shown the dyke to have been built just as the Ericaceae pollen had reached its maximum, the soil structure being a podzol over podzol, forming since the early-medieval period on a podzol that started forming in the Bronze Age. Based on this evidence, this particular dyke would then be appreciably earlier than the other three dykes Crampton investigated (Bwlch yr Afan 02265.0m, Ffos Toncenglau 02261.0m and Bedd Eiddil 02266.0m) (Lewis 2006).