NEHL - A coal shaft for coal is located here on the 19th century Ordnance Survey maps. Hett is known to have featured a medieval coal mine, however the location isn't exactly known. Given the location of this site it is well plausible to be used centuries before, however the shaft isn't documented on the 1839 tithe apportionment.

The shaft is now at least covered over by turf and capped.