Pencader Tunnel

Pencader Tunnel is an abandoned railwaytunnel on the old trackbed of the Carmarthen to Aberystwyth main line in south-west Wales. It was originally bored for the Llanpumsaint-Pencader section of the Carmarthen and Cardigan Railway (C&CR).

It is approximately 988 yards (903 m) long (just over half-a-mile), making it the longest tunnel in West Wales and is bored through Ordovicianshales. It is single-track and built to the C&CR's adopted broad gauge dimensions, as opposed to the smaller standard gauge used on Britain's railways today. It is also known as alternatively Alltwalis Tunnel and Dolgran Tunnel to local villagers.