1. Site of Elan aqueduct known as 'Dol-y-mynach Tunnel'. In field only marked by early 20th century red brick suspension bridge. Square 40cm wooden box on red brick support pillars on either bank of stream. Runs N-S. (RSJ 2000)
2. The 1 mile 437 yard long Dol-y-mynach Tunnel (inlet (S) end is nprn 309538, outlet (N) end is nprn 261172), carries water from Dol-y-mynach Reservoir (nprn 309539) to the Foel Valve Tower (nprn 32527), thereby making available the waters of the Claerwen River to the Scheme (nprn 96459).
B.A.Malaws, 28 November 2003.