The highway's southernmost spot is a beloved local attraction.

Minnesota's oldest and deepest mine is now an underground physics laboratory.

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.

A place for ship-lovers to watch the passage of freighters traversing the Great Lakes while learning about their history.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

An entire city block built completely out of petrified wood.

Known as "The Hill of the Little Devils."

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

A monument to the forgotten French explorers and their landmark expedition.

A unique blue and yellow phone booth in America's "Little Sweden."

An abandoned bus station transformed into a museum dedicated to the history of Greyhound Lines, in the place where it all began.

Home to part of the world’s largest private collection of original manuscripts and documents.

This rare vessel mixed luxury with labor before being converted to a museum and sometimes haunted maze.

The watery grave of an impractical idea.

This posh mansion began as a family's estate and ended as the site of a murder ripped from the pages of a pulp novel.

Just a man taking his prehistoric pet for a stroll.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

This giant roadside goose has been hailing travelers into a small Ontario town for over 50 years.

This vast kitty-themed collection illustrates the history of human-cat interaction.

The highest point in South Dakota contains the ashes of Valentine McGillycuudy, the "Holy White Man."

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.