Caldon tunnel

The Caldon Low tramway tunnel is a favourite of mine even though it is such a pain to get into due to the collapsed trees in the entrance cutting. I went back last year and got almost to the west end before the ochrey gloop overtopped my wellies. This was the fourth line to be built connecting the Caldon Low limestone quarries with the canal and limekilns at Froghall. It operated as a series of self-acting inclined planes and was 3ft 6ins gauge. Closure came in 1920.