A reservoir for the Aberdaunant mine, NPRN 402057, is shown here on the 1st edition Ordnance Survey map of 1886. A dam, NPRN 534787, was used to block the tributary stream to the Nant Gwestyn and the water diverted into a leat from the eastern corner of the dam. J.J. Hall, Trysor, 5th July 2013