Type 'easy' or 'hard' to begin the quiz. Easy is a 1-degree range, hard is a 0.5-degree range. Then, name any 10K+ Europe city in each longitude range which fits the category label for each square.
LETTER: means the city starts with that letter.
NUMBER RANGE: (such as 2-5, 10+) means the city contains that many letters (excluding spaces and special characters).
POPULATION RANGE: (such as 250-500K) means the city has that range for its population.
2+ WORDS means the city name has 2 or more words (words denoted by a space or hyphen).
At the end of the quiz the largest population missed answer will show in each range.
Quiz Takers 
I encountered a weird error – I typed in Spain and it brought up a list of what I presume to be the largest cities per letter per country, sorted by population. I typed in a bunch of cities it would “take” my answers but nothing was revealed and my score was [answers]/0. I kind of have an unbeatable score in Spain now though, lol.
Forgot to add – issue was gone on refresh. Probably just an issue with not loading the country – the country listed was on the side, but it was clearly pulling from all European countries.
hmm must be a one-off bug – i’ll remove that score.
For the Netherlands, you included a category which starts with an apostrophe (‘). The answer for that character is given as ‘s-Gravenzande, while ‘s-Hertogenbosch is the given answer for ‘S’. ‘s-Hertogenbosch is correctly written with an apostrophe though, and should be the answer for that category instead of ‘s-Gravenzande. Or you could remove the ‘-category entirely.
yeah I’ve fixed this – the apostrophe shouldn’t have been included as a letter.