Sixth Ave and 41st Street, Brooklyn.

Directions: Sixth Ave and 41st Street in Brooklyn, near the athletic courts.
N/R train to 45th Street in Brooklyn.
Walk 5 blocks north to 41th Street
Then walk 2 blocks east to 6th Ave, at the entrance to the park.
or
D train to 9th Avenue
Walk 3 blocks west along 38th street
Turn right on 6th Avenue, and walk 2 blocks south to the corner of the park.