"Un avión vuela sobre la ciudad."
Translation:A plane flies over the city.
SpanishDict lists "to explode" as an alternative translation of volar, which would alter the meaning of this sentence dramatically...
I think that the best translation is "city" since the words are nearly the same between Spanish and English. A town is usually a smaller, less-organized place. Cities have higher populations. They have centralized governments that wield much more power. It's a decent mistake to label a town as a city (or vice versa).