How can I make a url like /united-states/cities/new-york

How can I make a url like "/united-states/cities/new-york" intead of "/countries/1/cities/1" (I dont't want the word "countries" in the url)

what do I have to write in route.rb to use:

site.com/united-states/cities/ (to see united states' cities list)

site.com/united-states/cities/new-york/ (to se开发者_如何学编程e new york details)

and how use these routes in views and controllers?

Any ideas how to do this? cheers

http://railscasts.com/episodes/63-model-name-in-url

class Country
    def to_param
        @name
    end
end

class CountryController
    def show
        @country = Country.find(:name => param[:id])
        # ...
    end
end