Referring to Manhattan as 'the city' is very common: http://gothamist.com/2012/05/21/do_you_refer_to_manhattan_as_the_ci.php http://gothamist.com/2012/05/21/do_

Referring to Manhattan as 'the city' is very common: http://gothamist.com/2012/05/21/do_you_refer_to_manhattan_as_the_ci.php http://gothamist.com/2012/05/21/do_you_refer_to_manhattan_as... Whether it's capitalized is just a matter of taste, as seen in the comments.