Everyone who hasn't even been to New York has some sort of vision of how this city looks like: it's in so many songs, movies, TV shows and books that it's hard not to....
We all know that Philly stays jiggy (as Will Smith says). Philly is a cool place for a weekend getaway from NY, especially if you're there for longer and you want to see the US outside of NY (because it's a completely different thing). Philly cheesesteak sandwiches are worth the trip by themselves. In between meals you might also want to go see the National Museum, Independence Hall and Liberty Bell.