Can you mention all urban areas with over 100.000 inhabitants, that are over 500 kilometers away from any other urban area with over 100.000 inhabitants?
Data from citypopulation.de
Distance between cities taken from gps-coordinates.org
I'd like to point out that this quiz might be missing out on various cities that I missed during my (not so extensive) research, so if you notice some obscure city that is missing from the quiz, I'd be very thankful if you could point it out!
I pretty much made this quiz with Honolulu in mind, but it turns out there is a separate urban area (don't remember the name off the top of my head) that has just over 100k, and so it cancels Honolulu out.