This is the 11118th most frequent Russian word.
городами
The Russian word "городами" means "by cities" or "with cities" (instrumental plural of "город" – city).
In this sentence, 'городами' is used in the instrumental plural form to indicate association or relationship between two cities.
Между этими двумя городами пролегает длинная река.
Between these two cities lies a long river.
Here, 'городами' serves as the instrumental plural form, denoting the means or method — traveling through the medium of cities.
Он путешествовал по различным городами нашей страны.
He traveled through various cities of our country.
In this context, 'городами' describes the plural form of cities in the instrumental case used for characterization.