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

This statue of the "father of television" stands prominently in the United States Capitol.

The walls of the iconic dome are hollow and have a secret stairway.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

Look closely and you’ll notice that the color changes a third of the way up the tower.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

This unassuming passageway played a key role in one of the most important events in U.S. history.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

The naval commander’s proudest moment in battle is memorialized in this unique tomb at Arlington Cemetery.

The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

A much-maligned monument to teetotalism.

A spectacular tribute to statesman and philanthropist Andrew Mellon.

The "lovely red Vega" of the legendary record-settling pilot.

A line of blue paint marks the route of the inaugural parade.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

The tunnel under the Capitol Building where Congress takes out its trash.

At the time of its completion, it was the tallest dam in the world.

In 2010, Nicolas Cage purchased two plots in this cemetery using one to construct this strange pyramid mausoleum.

The final resting place of New Orleans' most famous voodoo priestess.