This was a Heritage walk I went on; the guy that led it really knew his stuff Amazon.co.uk: Mike Osborne: Books, Biogs, Audiobooks, Discussions
All these photos were taken at Freiston Shore, a few miles from Boston. The land in front of the original sea bank on which the defences are has been reclaimed since the war; it would all have originally been beach. Very bleak for a lot of the time for those who were stationed here, possibly a mix of regular troops and the Home Guard. Incidentally, one thing I learnt on the walk was that there were women members of the Home Guard, not something you'd know from watching Dad's Army!
#1 A couple of goats use it as shelter!
The gun would have fitted on here
The present sea wall is in the distance
The chains hanging from the ceiling probably supported nets which would stop the cordite smoke from being observable to enemy ships being fired on
The rear of the gun emplacement
The rods also helped support the nets; you can see a munitions store
Crew's rest area. Room for two sleeping and resting places at each end of the building
There would have been a stove here
Back at gun emplacement #2