Ping: I should have mentioned that you can click the first picture for a twice-the-size full-size version.
Hmmmmmn.
Pothole seems a poor term: more related to holes in a formed surface like a road.
So, since a sinkhole is formed differently than a "rockhole" (if the rockhole is formed by erosion of solid rock by falling water, and a sinkhole is made by loose water-soaked soil falling down), then what would they term the world's largest sinkhole?
Couldn't also be a pothole I would say.