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

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

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

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

This hidden treasure provides a charming access point along the south side of Baker Park.

According to local history, this cast-iron canine was nearly melted down for bullets during the Civil War.

The Cold War-era "underground Pentagon" is a sprawling subterranean hideaway for the Defense Department.

This memorial honors five journalists who were killed in a mass shooting in 2018, and affirms the importance of the first amendment.

This statue honors the author's groundbreaking family story.

One of the oldest active carousels in the country—but it might be missed by all but the keenest-eyed boardwalk strollers.

The land is home to swimming ponies and a legendary 18th-century treasure.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

A hidden three-foot-wide house separates these two regal churches.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

Elaborate tile work in this railway station tells the story of Portugal.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A 16th-century Andalusian palace.

The final resting place of the great navigator, or maybe his brother.

Hidden behind a wall, Spanish nuns distribute their signature sweets on a revolving tray.

The world's largest wooden structure.