The first declared National Monument in the United States.

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

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

In which a local geological marvel becomes a quaint roadside attraction.

Don't get it twisted: This is the oldest pretzel bakery in the United States.

A comprehensive collection of toy and model trains, largely from the mid-20th century.

This vintage short line in Amish country runs passenger steam train excursions and still hauls freight.

A huge railroad museum with over 100 pieces of rolling stock focusing on the railroad history of Pennsylvania.

This extraordinary model train layout covers over 1,700 square feet, with multiple trains running simultaneously.

A diorama of the Civil War, fought by cats.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

This Civil War monument was designed by an eccentric architect and Gettysburg veteran.

The site of America's first commercial oil well essentially disappeared after the town went bust.

Where the oil industry began.

Priceless space junk on display in front of a local Dairy Queen.

An abandoned railroad tunnel transformed into a creepy path for hikers and cyclists.

The oldest continually operating golf course in the United States.

The aggressively banal name of this underground fortress of bureaucracy does little to evoke its truly surreal existence.

An otherwise quiet campground becomes a bustling medieval town for two weeks every year.

A soon-to-be-forgotten roadside spectacle loaded with local lore.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

"Where the ducks walk on fish."

A tradition unlike any other, this marks the site of the annual Groundhog's Day tradition.

Tucked away in the forests of North Florida resides a 19th-century lighthouse.