a ride on the Strawberry Line

It's a sound the former railway tunnel probably hasn't heard in a while. Somewhere in the dark stands a honking, part owl, part abandoned steam train. My sister Ele has stopped on her bicycle and is blowing determinedly like a whistle over her cupped hands. As she recreates this long-gone sound, I continue to pedal through the cool, moist air. Water drips steadily from the stalactite-covered brickwork as my headlamp illuminates the pedestrians and their dogs emerging from the echoing shadows.

We're cycling the Strawberry Line, a 17.75-mile, largely off-road cycle and walking route from Yatton to Cheddar in north ...