A Steep Descent

This narrow road is called Tower Causeway (no tower anywhere, so I don't know why) and leads off the moor down into Portsmouth (no - not that Portsmouth)  between Todmorden and Burnley.
It disappears out of sight, twists and turns, and emerges on the main road 250ft below.
You can see the A646 Todmorden - Burnley road to the right alongside the railway line.