Sorry to drag up such an old thread, but I'm new here! If anyone does have any info about Munion Field, I'm interested as well. I've seen it on old maps, but never found anything about it. I even once asked Elizabeth Morgan about it and she didn't have anything.
There's some grass. The only thing intersting about it besides wondering why it was on maps, is that about 10 roads meet up there. It must have some history but it seemed devoid of evidence of former structures and everything else. It's easy to get lost out there too.