Mount Rushmore National Memorial, S.D.: This landmark, the result of 14 years of sculpture by demolition and chisel led by Gutzon Borglum and his son Lincoln Borglum, was completed in 1941. www.nps.gov/moru/index.htm
Gateway Arch, St. Louis: This 630-foot-high stainless-steel structure, part of the Jefferson National Expansion Memorial, was designed by Finnish American architect Eero Saarinen and completed in late 1965. (A new museum and visitor center are due to open in 2017.) www.lat.ms/stlouisarch
National Mall and Memorial Parks, Washington, D.C.: The Washington Monument (dedicated 1885) is the oldest of these nine sites, also known as America's front yard. The eight others are the Lincoln Memorial (1922); National World War II Memorial (2004); Thomas Jefferson Memorial (1943); Vietnam Veterans Memorial (1982); Martin Luther King Jr. Memorial (2011); Korean War Veterans Memorial (1995); Franklin Delano Roosevelt Memorial (1997); and the District of Columbia War Memorial (commemorates World War I; 1931). www.nps.gov/nama
Mesa Verde National Park, Colo.: This was the first national park to celebrate a man-made wonder _ a set of cliff dwellings built in the 12th and 13th centuries. www.nps.gov/meve
