First choose the number of cities by typing ‘100’, ‘250’, '500', '1k' or 'all' – then try to achieve the highest population among the largest English cities (min 500 population) you chose. Quiz is not timed.
hugequiz Premium users have the option to choose any number of cities to play the quiz with (stats are processed but score isn't saved). Simply enter #(number of cities)# to play the quiz with any number of cities from 25 to the maximum. For example, to play the 300 largest cities, type #300# to begin the quiz and you will play it with the 300 largest cities. Entering #all# will play it with all cities - all cities will also be chosen for any number chosen above the total.
Quiz Takers 
surprised to see iasi on here
In their native language both Cologne and Vienna would count since their names in German are Köln and Wien, both one syllable.
Yes but I’m using English versions of names for this quiz.
What about Kielce and Trier?
Gdańsk is listed as two syllables on the Wiki page, with the audio sample in the Name section instead of in the opening paragraph.
Will add those two. I have Gdansk as one syllable in my other quizzes and native Polish speakers (I speak some myself) do pronounce it as one syllable.
I thought Lyon had two syllables.
In the French pronunciation the two parts are diphthongs, I am counting those as one syllable.
Player from Lyon here : definitely one syllable in French pronouncing.