D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

A much-maligned monument to teetotalism.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

A historic arena where the Beatles played their first concert in the U.S.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

The United States Capitol's former columns still stand.