High Quality Content by WIKIPEDIA articles! Grand Army Plaza in Brooklyn, New York is an 11-acre (4.4 hectare) oval plaza that forms the main entrance to Prospect Park. It was designed by Frederick Law Olmsted and Calvert Vaux in 1867. It consists of concentric rings arranged as streets, with the outer ring being named Plaza Street. The inner ring was originally intended to be a circle, but it actually was arranged as a main street Flatbush Avenue with eight radial roads connecting: Vanderbilt Avenue; Butler Place; Saint John s Place (twice); Lincoln Place; Eastern Parkway; Prospect Park West; Union Street; and Berkeley Place.