1. The first railway tunnel used by a railway locomotive.
RCAHMW, 01 January 1993.
2. Tunnel, built in 1802-3, carrying the Merthyr Tramroad (nprn 91513) under the furnace charging bank of Plymouth Ironworks (nprn 34114). The original tunnel has been extended to the south. The northern end is buried and both tunnels are currently inaccessible, but the south portal of the later tunnel has been 'restored', with new stonework, steel grille, mosaic blocking wall and flooring, &c.
B.A.Malaws, RCAHMW, 23 January 1992.