It's a great walking town as it's so flat. Head to Strawberry Fields the tribute to John Lennon in Central Park, the Dakota Bldg where he lived and was shot in the Upper West Side. Head to Chelsea, the Village and Washington Square Park, Soho, Chinatown, Little Italy, the Lower East Side...you can easily walk 60 blocks in an hour or so.
"When I was young, I was sure of many things; now there are only two things of which I am sure: one is, that I am a miserable sinner; and the other, that Christ is an all-sufficient Saviour. He is well-taught who learns these two lessons." -John Newton