Pentre-bach quarry (nprn 403712) was connected to a wharf on the Glamorganshire Canal (nprn 34425) by a short tramroad carried beneath the turnpike road in a tunnel at ST 08106 89911.
(A Guide to the Industrial Archaeology of South East Wales, AIA, 2003)
B.A.Malaws, RCAHMW, 10 November 2005.