Landmark 85 Brecon Mountain Railway, nr Pontsticill, Merthyr Tydfil-Powys Built on the trackbed of the former Brecon and Merthyr Railway, it operates over 3½ miles of 2-ft gauge track from Pant to Dol-y-Gaer, though its ultimate destination is Torpantau, location of the highest railway tunnel in Britain. Skirting the picturesque Taff Fechan reservoir at the foot of the Brecon Beacons, there is a small Halt at Pontsticill where passengers can detrain to picnic or to take a walk into the forest.