Four abandoned tunnels on the Manchester and Milford Railway

The Manchester and Milford Railway, says Wikipedia, was a Welsh railway company, intended to connect the industrial areas of Northwest England with a deep-water port on Milford Haven, giving an alternative to the Port of Liverpool.

Its object was to be achieved through linking existing railways, and the only new track the company built was between Aberystwyth and Carmarthen in rural West Wales.

That line closed in 1965, and this video sets out to find what remains of four tunnels on the line.