garlock wrote:When you say "armoured plate," are you referring to metal?
Yes, a steel plate. bunkersite.com shows some examples.
Also, the photo shows only part of the structure. Does this look like it is a discrete structure, or could it be only one gun emplacement in a larger fortification? It is probably not possible to tell.
I can't give you a definite answer, but most German bunkers had a very specific purpose.
It's probably a small gun emplacement.