A city is a game mechanic. It's an entity type. If you want to construct a facility, your location must be a City entity. So a lot of people have placed additional cities ready for building in them, and either not gotten around to it, or not had the money to do so.
So a city DOES have features. But those features are the ability to build facilities and roads in it.
"May the Grace of Ara go with you, and His Vengeance be wrought upon your enemies."