On Manhattan's Upper West Side, alongside Central Park, there are some really beautiful buildings, many of which have interesting architectural details:
This avenue, Central Park West, features some of the most expensive residential real estate in all of Manhattan.
For a pleasant stroll of maybe an hour or so in duration, walk north from Columbus Circle (at 59th Street), up 8th Avenue/Central Park West, to 75th Street or so. You'll see a wide variety of buildings with many unusual architectural details.
And you'll see a lot of doormen.