A strangely forgotten claimant to the much contested title of "Source of the Nile."

Where the White Nile River dramatically cascades between Lake Kyoga and Lake Albert in Uganda.

A public urinal so pretty, it was declared a national monument.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

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.

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

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

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

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

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

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

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

There’s a hidden military meme engraved on the World War II Memorial.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

Designed to honor all those that work as nurses around the globe.

Statue commemorating the use of ether in anesthesia.

The site of Paul Revere's historic two lantern warning.

19th-century operating theatre in which the use of ether was first demonstrated - plus, a skeleton and a mummy!

A vertically floating hemlock controls the waves and weather at Crater Lake.