If you want to see how big Central Park is then take a trip up to the rooftop sculpture garden at the Metropolitan Museum of Art. From there you can see the tree tops from end to end and all the buildings bordering the park. It is truly amazing.
Today they opened a new exhibit by Jeff Koons that runs through October. Make sure there is no rain in the forecast though, I have spent the $20 to get up there before only to be barred from enterring.