The skyline of Washington, D.C., including the Lincoln Memorial, Washington Monument, U.S. Capitol and National Mall, seen on June 15, 2014.

The skyline of Washington, DC, including the Lincoln Memorial, Washington Monument, US Capitol and National Mall, is seen from the air at sunset in this photograph taken on June 15, 2014. AFP PHOTO / Saul LOEB (Photo credit should read SAUL LOEB/AFP via Getty Images)