Very interesting and informative video describing how the Washington DC National Mall was designed. The National Mall is a national park in downtown Washington, D.C., the capital of the United States, and is the center of most tourism in DC.  It's a lovely tree-lined open space from the U.S. Capitol to the Lincoln Memorial with the Washington Monument in the middle, and also includes the Memorial Parks and areas that are officially part of West Potomac Park and Constitution Gardens. Ten of the Smithsonian Institution museums are situated along the Mall.