Before requesting a city, please take a look at google earth first to find out if there is no city that is too close to it.
What is too close?
Cairo and Alexandria are too close.
They are the exception as it happened.
It has to be a little further from eachother then that.

Also for the moment, try to avoid ANY cities in Europe unless you find a country that has no or perhaps just 1 city.
Same goes for America.
Time to fill those empty spots, not make crowded places TOO crowded.
Example: If you have a city in Holland you like to see added, then I'm very sorry. It would be too close to Amsterdam to add.