One of these places in Oslo contains a sculpture a
One of these places in Oslo contains a sculpture arrangement by Gustav Vigeland, while another of these in Barcelona contains a mosaic fountain in the shape of a salamander. Those examples of these places are called Frogner and Guell. One of these in London contains the Speakers' Corner, adjoins Kensington Gardens, and was the site of the (*) Crystal Palace. The Metropolitan Museum of Art is located on the grounds of the most famous one of these in the United States, which is bordered on the east by Fifth Avenue and was designed by Calvert Vaux and Frederick Law Olmsted. For ten points, identify these usually grassy areas exemplified by a Central one in New York City.
One of these places in Oslo contains a sculpture arrangement by Gustav Vigeland, while another of these in Barcelona contains a mosaic fountain in the shape of a salamander.