The biggest water area in Central Park was originally named "Central Park Reservoir". Eventually, in 1994, it was renamed and nowadays it bears the name of the former first lady of the United States - Jacqueline Kennedy. The track around it is a popular one for a jog among the locals (even among the local celebrities, such as Madonna).
Wikipedia https://en.wikipedia.org/wiki/Jacqueline_Kennedy_Onassis_Reservoir
Official Website http://www.centralparknyc.org/things-to-see-and-do/attractions/reservoir.html
Address Central Park, New York City, New York 83, USA
Coordinates 40°47'9.418" N -73°57'43.321" E