The massive earthwork pondbay, or water collection tank at Allt-y-Brunant measures 14m north-east to south-west by 9.0m. It is set on north-west facing slopes, that would appear to have been fed by a spring in its south-eastern corner. This can be compared with similar features that form part of the water supply complex for the Roman goldmines at Dolaucothi (see Nprn95141).

(source Os495card; SN64SE5)

J.Wiles 07.01.05