A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

The highest point in Delaware is located under a trailer so this marker across the street will have to do.

This collection of odd proofs of concept is like taking a walk through the imagination of a Victorian engineer.

Enchanting gardens surround a derelict mansion, all hidden in plain sight behind a stone wall.

This weeping, 10-foot-tall sculpture was a maquette for a 9/11 memorial.

A castle inspired by medieval architecture is hidden in the woods of Connecticut.

The final resting place of one member of the Amistad slave revolt who never made it back home.

This tribute to the founding father of the American dictionary originally contained a spelling error.

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

A daily replay of the experiment that proved the rotation of the Earth.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

Believed to be the birthplace of the United States Marine Corps.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

This tiny structure was built by the creator of the Brooklyn Bridge.

One of New Jersey's oldest surviving buildings still bears the mark of our former British overlords.

Mysterious rocks that ring musically when struck.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

A blend of art, antiquities, and Americana fill this museum, surrounded by whimsical, enchanting gardens.

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

The only Leonardo Da Vinci painting in the Western Hemisphere.

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

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

"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!”