New York's green spaces receive well over 100 million visitors a year, according to Parks Department spokesman, Arthur Pincus. Central Park is the showstopper, hosting 40 million park goers annually.
New York devotes nearly 20% -- more than 38,000 acres -- of its land to green use. And most of that land is quite valuable: Central Park's acreage alone is estimated to be worth more than half a trillion dollars, according to Jonathan Miller of Miller Samuel, a New York real estate appraiser.
Related: 10 big, booming cities
The park system extends far beyond Manhattan to include ocean beaches in Staten Island, upland forests in the Bronx and re-purposed industrial sites, like the old Domino Sugar plant property in Brooklyn.
In recent years, the city has reclaimed much of its waterfront and established new parks along the Hudson River in Manhattan and along the East River in Brooklyn and Queens.
