The National Mall (http://nps.gov/mall/) is the monumental green space at the heart of Washington, D.C., the heart of the national psyche, and the heart of civic America. This national treasure stretches for two miles just south of the White House, from the U.S. Capitol Building in the east to the Lincoln Memorial and Potomac River on the west. The park is home to the Smithsonian, a huge collection of the nation's best and free museums, as well as most of the country's most famous memorials and monuments. It is the number-one destination for visitors in the city, and one of the biggest destinations in the country.