The Glynneath Incline is an 800 metre formation built as part of the Cefn Rhigos Tramroad in 1803 to 1805 in order to connect the ironworks at Aberdare with the Neath Canal. It follows a line from National Grid Reference SN89130654 to SN89920631, in cuttings and on embankments and is generally well preserved. It is also known as the Pont Walby Incline and Abernant-Glynneath Tramroad Incline.

The winding-engine house (NPRN 309279) site is immediately south of the trackbed at the eastern end of a short level section at the top of the incline and is visible as a sunken earthwork. The top of the embankment, just below summit level, is approximately five metres wide, measured between the outer rows of stone sleeper blocks representing two tracks. The trackbed in the cutting to the west is approximately seven metres wide, including a small drainage ditch at each side and several stone sleeper blocks are visible.The incline earthworks have suffered only minor damage from crossing farm tracks. The site was visited by B.A.Malaws of the RCAHMW on 6 February 1992.

Sources:
Site notes of B A Malaws and Stephen Hughes, RCAHMW
Hughes, S (1990) 'The Archaeology of an Early Railway System,The Brecon Forest Tramroad, p.316' RCAHMW

RCAHMW, 17 October 2011.