There is nothing at the posted coordinates - This is the bonus cache for the nearby Adventure Lab cache which can be accessed here :-https://labs.geocaching.com/goto/Helstonhistory or by looking at the Adventure Lab app which is available for most smartphones.
The coordinates for the cache container can be found by completing each stage of the Lab cache which entails visiting 5 locations within the town.
The five locations are all within walking distance of the town centre where there are numerous car parks.
Once you have collected the 5 numbers, enter them in the following equation :-
N50 06. (C-D) ((B+E)-C) (A-E) W005 16. (A-E) (B-E) (C+E)