The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The city is full of whimsical portals to another world.

Learn about Iceland's hidden folk at this school dedicated to the study of elves.

Robots, lasers, and whoopee cushions, oh my!

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

The first declared National Monument in the United States.

A place to eat for on-the-run agents and espionage enthusiasts.

Statue dedicated to the star of an old television show.

This is one really big nut.

A curiosity-seeker's paradise set inside a three-story historic school house.

The Midwestern United States' tribute to Michelangelo is a foam statue sprayed with gaudy gold paint.

The largest cemetery in Louisville is the final resting place of Col. Sanders and Muhammad Ali.

This 19th century mansion façade adorned with immigrant patriotism is a symbol of Louisville’s history.

The oldest operating Mississippi River–style steamboat still navigates the Ohio River.

The grave of the iconic Kentucky Fried Chicken mascot features a bust of the man behind the goatee.

This former tuberculosis research hospital endeavored to cure the dreaded disease with fresh air and positive attitudes.

This black shoreline is made up of exploded lava particles.

This psychedelic tromp l'oeil seems to be beckoning drivers to crash into a wall.

This titanic steel chain linking two buildings was installed without permission but instantly beloved.

The world's largest fire hydrant is supposedly tornado-proof.

Half-sized replica of the Leaning Tower of Pisa built to honor Galileo.

Recognized the world over as the home of the McCallisters in the 1990 movie "Home Alone."

This "zoo" is a cross between a junkyard and a sculpture garden, featuring animals you won't see anywhere else.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.