I'm pretty sure 'cities' is a plural noun. It is not a possesive noun becuase unless you had another word with it, it can't be possesive alone Like.... The woman's car. This sentence has a possessive noun right before the word car. Car is the direct obeject of the possesive noun. What kind of car? The -an article I don't know for certain of that is accurate. Look at grammar websites for an even more accurate response