Wow!
I tried looking into this, and the best I can come up with is a little French town called Saint Malo or maybe Alteh.
There's a
good web site on it here. Which is where I found this old picture of a different pillbox in the area.
Seems these pillboxes sit on top of bunkers, so whoever was inside could have climbed down a ladder and run out the back of the hillside when the first few shells were glancing off the sides and weren't hitting directly yet.