It's a funny cultural thing that it wouldn't have even occurred to me that someone in Europe wouldn't realize city names can conflict—it's a chronic problem here in the states.
There are some ridiculously common city names here, but one that's been in the news lately and probably confusing a lot of people is Springfield, which is the name of at least 42 different cities in the US [0], including 5 just in Wisconsin. Most of them are small, but 5 of them (Massachusetts, Missouri, Illinois, Oregon, Ohio) have more the 20k residents.