A small watercourse near Rochdale flows in an easterly direction into the River Spodden. A stone dressed outfall leads to a vaguely circular tunnel around 4ft and later opens up to brick arch around 5ft tall. I managed to get around 150m before a downpour from a shaft above removed my desire to continue.
There's potentially more to be seen with a way of getting past without getting absolutely soaked.
There's potentially more to be seen with a way of getting past without getting absolutely soaked.