A hole in the desert

[Ellip]

And With 30km not a small one.

The Crater isn`t listed in the Crater list.

Anyone an idea ?

[Steeefan]

After doing some research using the name to that 'thing' which GE gives us, I found the following.Guelb er Richat is a circular crater-like geogolical shape at Sahara (Mauritania) It's diameter is 45km, the circlic walls are only a few meters high.

At first it was mistaken for a crater caused by a meteor but research proved that it's a vulcan which isn't erupted.Info from NASA (http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=9319)

[Stadsman]

Nice find. My guess is that it's an oasis or underground lake that periodically dries up (Turn on the water layer to see where the water is). It's also very near a Keyhole Community BBS placemarker (turn on that layer to see it), which refers to a UNESCO World Heritage Site, see link (http://whc.unesco.org/pg.cfm?cid=31&id_site=750).

[Viking]

Just spent some time panning in and out over ... whatever that thing is .... it's huge!

[Rwootton]

Apparently it is a symmetrical uplift (circular anticline) that has been laid bare by erosion

source:
http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?
img_id=2124

Ooops this is nearly identical to Steefans post, sorry