The man made hole is so large that helicopters and small aircraft can not fly near it without the very real fear of being sucked in!

Spot Cool Stuff has been thinking of cool spots lately. Big geologic spots, that is. Circles on the face of the planet of the sort that would make some one browsing around on Google Earth (or traveling in a spaceship) stop and ask What the heck is that circular thing?

Here’s an overview (literally!) of seven of our favorite such spots. They span six countries on four continents:

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