Chelsea piers used to be old broken down docks and piers on the west side of manhattan on the Hudson. Many years ago the cruise ships used to dock there. Then they just sort of rotted and became a nasty, funky neighborhood in the Chelsea part of town (20th street up to about 34th to maybe 42nd Street), from about 6th Ave (now Ave of Americas all the way over to the Hudson about 11th or 12th Ave - West End Avenue, West Side Highway).  Now Chelsea piers are a fun place to go to play golf, hit baseballs, play tennis, rock climb, go bowling, shop, get ice cream, snacks, health food - I think the food network might even have been located in those buildings. Great for kids big and small. 
About Suri's outfit - who dressed her?  She's wearing a blouse with tights and a faux fur jacket which is too small. If she's wearing a dress it's too small too.  She looks a wreck.