in Washington, D.C., broad promenade and greensward extending westward from the Capitol to the Potomac River beyond the Lincoln Memorial. The Mall is as wide (in the north–south dimension) as the grounds of the Capitol; it is bounded north by Constitution Ave. and south by Independence Ave., and it is crossed east–west by (from the north) Madison, Washington, Adams, and Jefferson drives. Set within the Mall or flanking it are numerous institutions: the National Gallery of Art, the National Museum of Natural History, the National Museum of American History, the Freer Gallery of Art, the Smithsonian Institution headquarters, the National Air and Space Museum, the Arts and Industries Building, and the Hirshhorn Museum and Sculpture Garden. West of 14th Street are the Washington Monument, the Sylvan Theater, a portion of the Tidal Basin, the Reflecting Pool, and the Lincoln Memorial.