Harlem Meer is a great place to take a break from the fast pace of everyday life. See if any water activities are available here, or simply soak up the peaceful ambiance.
You'll have no end of sightseeing choices when spending time in Manhattan. Harlem Meer is a great place to kick off here, but there are many other interesting attractions to experience. Times Square, Broadway, and Grand Central Terminal are close to the body of water and and will cap off your day nicely.