This could be anywhere in the world, but I can't help but think southern California with the look and attitude. Great photo...you really isolated the girls from background perfectly!
Interesting take on the challenge. I fear for the DNMC votes you may receive because there is no street. (I however am not so narrow minded). Nice colors and the background, though blurred, has sufficient detail to provide context for the subjects.
The fact they are looking across the frame helps as well. It draws the eye across the picture nicely. Because of this, perhaps landscape orientation might have worked well rather than portait.