Funnily enough, I thought of this thread when I came across a terrible....what turned out to be....mini roundabout, a few days ago.
It was a new area to me, so that did not help.
But, leading up to the actual roundabout, there were no signs at all regarding it on approach, and when you actually got there, it was just all very odd.

Initial approach, not a sign in sight.

Nearly at the give way, but the road condition is appalling and the lines are even less visible now. Your eyes are not even really drawn towards the tiny roundabout. Nor does there seem to be any give way lines on the entrance/exit to the right. It's so set back it is hard to tell if they are "on the roundabout" and have priority.

When you actually get to it, it did not feel like a roundabout at all. The wide angle of google maps makes it look better than it actually is.
Looking at it again in more detail, it seems like it might actually be a through road from the right hand entrance as i cant see any give way lines. The road diagonally across is a no-entry too.
So maybe it is some kind of quasi-mini-roundabout/island arrangement.