Just because it's such a cool image, really. This is a natural-gas pocket in Darvaz, Uzbekistan (thanks to montieth for the positive identification) that's reportedly been burning for 35 years. (Presumably no-one can figure out how to put it out.)

You did bring marshmallows, right...?
no subject
no subject
no subject
http://englishrussia.com/index.php/2008/03/25/darvaz-the-door-to-hell/
no subject
no subject
no subject
They do make pretty pictures...