Biggest European Cities by Letter - A

Alicante (330,000), Angers (150,000), Aix-en-Provence (140,000), Amiens (130,000), Ancona (106,000), Alkmaar (107,000), Amersfoort (155,000) ... all possible candidates for inclusion here.

Then there's Almere, Apeldoorn, and Arnhem (took me long enough to learn the Netherlands "A's").

Also Alcalá de Henares and Alcorcón in Spain.

Still, I enjoyed the quiz and learned about Arezzo and Altamura, and found out where the heck Aylesbury was.

Will continue with the series. :)

ps. Astrakhan, Arkhangelsk, Armavir.