Typically it's a somewhat crude Fenland construction, maybe it's a shed, a toolstore or garage but one with not a single splash of Norfolk Bog Door Blue to be seen.
Now that is unusual.
A corrugated iron roof smothered in ivy and a mossy deposit on the planking and some woodworm for good measure, I don't think I would dare to open the door, not unless I wanted the entire edifice to come crashing down around my ears.
The trouble with all of these derelict sheds, Nissen Huts and barns is that eventually curiosity gets the better of you and inevitably you simply have to have a peep inside to see what wonders, or junk as the boss calls it, can be found.
I'll report back.
Probably when you get out of hospital says the boss.