Jacqueline Kennedy Onassis Reservoir

        The Jacqueline Kennedy Onassis Reservoir (sometimes abbreviated by locals as JKO) – originally and sometimes still known as the Central Park Reservoir – is a decommissioned reservoir in Central Park in the borough of Manhattan.

The Reservoir covers 106 acres (43 ha) and holds over 1,000,000,000 US gallons (3,800,000 m3) of water.Though no longer used to distribute New York City's water supply, it provides water for the Pooland the Harlem Meer. It is a popular place of  interest; there is a 1.58-mile (2.54 km)jogging track around it and it is also encircled by the park's bridle trail.

The Reservoir was built between 1858 and 1862, to the design for Central Park of  Frederick Law Olmsted and Calvert Vaux,who designed its two pumphouses of Manhattan schist with granite facings. It was never a collecting reservoir. It was used to receive water from the Croton Aqueduct and distribute it to Manhattan.

After 131 years of service, it was decommissioned in 1993, after it was deemed obsolete because of a new main under 79th Street that connected with the Third Water Tunnel and because of growing concerns that it could become contaminated.It was renamed in honor of  Jacqueline Kennedy Onassis in 1994 to commemorate her contributions to the city, because she enjoyed jogging in the area,which lay beneath the windows of her Fifth Avenue apartment.