I should have placed something there to give some perspective, but if I recall it was in the 2-3 foot diameter range and there were no other depressions or anything similar near it.
I figure it's quite likely one or more of you have come across this same feature in your time exploring out there, so I was hoping someone could help me figure out whether this is just one of those natural features, or if it's something man made - and if so, what would it have been? I'll re-size the photo tonight so it's easier to see.
I'm going to follow this up with some other photos from that trip as well, but it might take a few more days.
