Kenilworth Park and Aquatic Gardens are to the west of Kenilworth Avenue along the Anacostia River, across the river from the U. S. National Arboretum. The park entrance is at1550 Anacostia Avenue between Quarles and Douglas Streets
From the Anacostia Park brochure
There are many on line maps you can use if you are not using the map above. The address for GPS is 1550 Anacostia Avenue, NE. The entrance to the park is between Quarles and Anacostia Avenue and Douglas and Anacostia Avenue.