5.7 miles, 1-3 hours
This is a great way to see all of the Monuments and Memorials of Washington DC, each unique and important in its own way. The walk starts at the White House and continues through the National Mall, along the Reflecting Pool, around the Tidal Basin, and eventually ends at the US Capitol Building and Supreme Court. This tour will take you through many significant eras in the history of the United States, including the Revolutionary War, Vietnam War, Korean War, World War II, past several memories to inspiring presidents such as Lincoln, Roosevelt, and Jefferson, and past all three branches of government.
On top of that, it is a scenic walk and quite relaxing depending on the time of year and the weather. After completing this walk, you will have seen most of the tourist destinations in Washington DC (other than the museums that surround the National Mall).
For a shorter version of the tour you can end at the Washington Monument after looping around the Tidal Basin rather than walking down the entire length of the National Mall towards to Capitol Building.