Pillbox at Friskney! Tipoff received, Skegness Video set off to investigate!
Oh! The tipster could have warned us that the exhibit was in a recently ploughed field, complete with peaks and troughs with an amplitude (seemingly) of two feet! Undeterred, no peak being too high, no trough too deep for Skegness Video, we squelchilly advanced to the target. (More onomatopoeic adverbs were added to, and subsequently banned from, the Oxford English Dictionary as we progressed!)
On site, we found not one, but a crop of four World War 2 pillboxes.
These are located as the red dots on the map below. (I have also highlighted Gibraltar Point where there is numerous military defense relics.)
The same map on Googlewill allow you to drag northeastwards towards Skegness, zoom, and view as satelite.