A spectacular tribute to statesman and philanthropist Andrew Mellon.

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

The only Leonardo Da Vinci painting in the Western Hemisphere.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

The National Park Service’s best-kept secret with views that rival any in D.C.

This unique museum cafeteria showcases the history and regional diversity of African American cuisine.

A computer bug so primitive it was an actual insect.

Seemingly unremarkable items like empty sushi trays, chef hats, and freshness stickers are being preserved so future generations can look back on this beloved cultural import.

This taxidermy horse was a Civil War hero.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

The most decorated dog of World War I is preserved in the Smithsonian.

The story behind this beloved toy—named for Theodore Roosevelt and owned by his grandson—is more complicated than you might guess.

This plaque marks the former home of one of the first women physicians in the Netherlands.

This vibrant side road in Doha was painted light blue to reduce heat.

The most accurate timepiece in the world.

Known as "The Spewer," this bizarre fountain has an even stranger urban legend behind it.

This cannonball has been lodged in the church wall since a 1695 bombardment destroyed the city center.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

This advertisement for talcum powder was painted on the rock face and has since defied removal.

This shale formation along the Appalachian Trail once inspired the third president of the United States.

Built in the 1850s, this church was of the first five churches constructed in Harper's Ferry.

Time travel with sweets across history at this research-based candy store.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.