Strong Street Playground, July 31, 2015. The New York City Parks Department says[1]:

This playground is located within Old Fort Four Park ... The City of New York first acquired this property, located at Strong Street and Reservoir Avenue, by condemnation in 1895 as part of the Jerome Park Reservoir proceedings. The Bronx Parks Department received jurisdiction in two parcels; the first in 1913 and the second in 1931, and the playground opened in 1934. The facility included a basketball court, paddle tennis, seesaw, swings, and a shower basin.

And a Parks Department press from 1941 says[2]:

The Department of Parks announces the completion, of work on the redesign of a play area on Reservoir Avenue between Strong Street and West 197th Street, The Bronx. This property was acquired by the Department of Parks in 1935, at which time it was graded and provided with see-saws and swings by relief workers. The current project represents an amplification of the original work. The area has been paved with a smooth bituminous surface to provide all year round usage. A sand pit and benches have been added, and new boundary fencing together with a new entrance on Strong Street have been installed. All work was performed by the Work Projects Administration from plans prepared by the Department of Parks.

References:

1. Washington's Walk: Strong Street Playground, New York City Parks Department website.
2. NYC Parks Dept press release of June 13, 1941.
3. New Deal Assistance in NYC Parks Department Projects, 1934-43.