In case of some countries, oficially presented borders for cities proper are much smaller than real built-up areas and borders for urban areas much bigger.
That's why I tried to do the quiz as comparable and accurate as possible and did a lot of research with the satellite images.
- Where the official data differ a lot from reality on the ground but there are available data for counting more realistic and more comparable figures, I did my own research with the satellite images.
- Where there are smaller cities, villages or settlements that are unquestionably part of the built-up area of a bigger city their figures were added to it.
- Where there are more big cities of similar size that unquestionably creates one continuos built-up area, they were grouped together and you can guess the correct answer by typing name of any of them.
You can argue with me here and there but overall it should be really precise and comparable. I spent huge amount of time on this quiz to make it really as precise and comparable among so many countries as possible.
And congratulations for reaching 100%! Even I, as creator of the quiz, have maximum only 671 / 683 after several attempts.