The North Yorkshire Moors Railway is Britain's most popular heritage railway, and runs for 18 miles through the national park of the same name. The journey commences at the market town of Pickering, whose station has a recently restored overall roof. It continues through remote Levisham and into the spectacular glaciated gorge of Newtondale and onto Fen Bog, where George Stephenson floated the railway on a bed of sheep fleeces and timber. Once over Goathland summit, the line descends steep...