I think anyone who knows the Roman Empire pretty well should get about 15 - 17 pretty quickly... then of the remaining choices, it should be pretty easy to eliminate all the ones that are definitely wrong, so the rest have to be correct. The last one I got was Cologne, as I was thinking which of the 2 German cities was more likely to be correct... but then it occurred to me first that the empire never extended as far east in northern Europe as Berlin... but also that the name "Cologne" came from the Latin "colonia".
Cologne was founded by the Romans around 30 BCE as a city called Colonia Claudia Ara Agrippinensium. It is actually one of the oldest cities in Germany. The border of the Roman empire in what is today Germany mostly followed the river Rhine. So there are many Roman cities west of the Rhine but essentially none east of the Rhine. Berlin was only founded in the 13th century and wasn't really relevant until the 18th century when it became the capital of Prussia. It definitely didn't exist during Roman times. We like to joke that while Cologne was already prospering for over a thousand years, Berlin was just a swamp - in fact, the name Berlin probably derives from a slavic word for swamp or bog. Greetings from Cologne ;-)
I only missed amman. I was fairly sure the one I clicked would be wrong, but the others all didn't seem too likely and I thought perhaps I am wrong about it being wrong and gave it a go, but nope indeed it was wrong.
Oh wow I got them all correct. Just remember that they stuck to western and southern Europe and the Balkans and the edges of the Mediterranean. They did not pass the Rhine Rivver