For those unfamiliar with the BMR, it is a 2ft gauge line built on part of the trackbed of the standard gauge Brecon and Merthyr Tydfil Junction Railway. The bridge which took the BMJR across the road just below the original Torpantau station was demolished after the line was closed in the 1960's, so the BMR currently stops at a new station just short of the old bridge site. The original station is now gone, and only a grassy area marks the site now. However, just beyond it is the Torpantau Tunnel, once the highest railway tunnel in the UK. The BMR have long planned to extend their line through the tunnel, but will need to replace the missing bridge first.
In this Youtube video, Paul Whitewick takes us on a short tour of Torpantau Tunnel. Paul's Youtube channel is worth following as he makes excellent videos covering abandoned lines and stations across the UK.I am in frequent contact with him personally.
Welsh Abandoned Tunnel - Torpantau