Limepits/West Ecton mine isn't massive, but it's worth a look in on (adit entrance just under the old railway line) - there's a flooded inclined shaft with a timber rope guide at the far end, and the choked connection to the engine shaft. There's also an upper adit which goes into a steeply dipping pipe working, and also into the side of said engine shaft, but you really need cowstails to visit it, and it's also difficult to find....
Follow the horses, Johnny my laddie, follow the horses canny lad-oh!