Type 'easy' or 'hard' to begin the quiz. Easy is a 5-degree grid, hard is a 2.5-degree grid. A random grid will be placed on the map. Then, try to name the THIRD LARGEST 10K+ European city in each grid square. To name a city, you must first click on the grid square to make it have a GREEN border. Then, type in the city answer for that square followed by a '.' (a period). You are given a score from 0 to 100 based on your answer's population compared to the 3nd largest city accepted in that square (100 being you named the 3nd largest city). If you guess the largest city it will be based on the ratio of the 3nd largest city's population to the largest.
At the end of the quiz the 3nd largest city will show in each unanswered square, and for those answered the 3nd largest city will be listed next to your score if you didn't answer it.
Quiz Takers 
I would love to see quizzes for the Prague, Budapest and Warsaw metro. I am so bad at the western European ones except for the Dutch ones.
I’ve added them 🙂
That’s amazing, you’re the best!
Please do one for the rotterdam metro too!
Here you go!
https://hugequiz.com/quizzes/rotterdam-metro-stations/
Nice to see those metro quizzes coming! Just one remark about this one – Sixhaven station was never built, although they left some extra space so that it could be finished and opened later. That is however not likely to happen anytime soon.
I will remove it – thanks!