Fork Candles!

Obviously these aren't candles.  For those in the UK of a certain age will remember the TV programme, 'The Two Ronnies' and one of the comedy sketches was a play on words when someone asks for FORK HANDLES, but sounds like FOUR CANDLES.  Nevertheless, whenever I pass these that sketch brings a smile.  Where am I?  Locals will know this is called Saltpans as there are two circular depressions constructed for salt production for the local landowner.  I'm unsure what these four pieces of wood were used four-maybe part of a jetty.  Those saltpans are below the Roman Fortlet 21 which is part of Hadrian's Wall.