What is the name of the 4.2 acre public garden in the Smithsonian complex, adjacent to the Smithsonian Castle on the National Mall in Washington?
National Mall The National Mall is a national park in downtown Washington, D.C., the capital of the United States. The National Park Service (NPS) of the U.S. Department of the Interior administers the National Mall, which is part of its National Mall and Memorial Parks unit.
Rainbow Pool The Rainbow Pool was a reflecting pool located on the National Mall in Washington D.C., USA. It was designed by landscape architect Frederick Law Olmsted, Jr., and was situated between the Lincoln Memorial Reflecting Pool (to the west), and 17th Street NW (to the east). The pool was renamed the Rainbow Pool on October 15, 1924 after it was noticed that its 124 nozzles created a "perfect rainbow" when turned on.