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

This shallow pit was once used to send over 20,000 buffalo plummeting to their death.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The first declared National Monument in the United States.

Miraculous tree that seems to sprout out of solid rock.

A monument to the egos of two railroad magnates that fell into decline along with their careers.

The high point on the 16th president's eponymous roadway is marked by a massive version of his head.

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

Fresh wooden posts have been added to ancient holes to recreate a primitive henge clock.

A pop-culture attraction outside of Dyersville, Iowa, hits a home run.

For just a few bucks, this Iowa funicular will let you feel like an 1800s fat cat.

Known as the "Cross At The Crossroads," this massive metal cross is just short enough to avoid the FAA.

The world's tallest doric column is this Ohio monument to a naval victory in the War of 1812.

This humble star-gazing center touts itself as the "Birthplace of American Astronomy."

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

America's only nuclear missile silo open to the public.

The world's largest military aircraft cemetery.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

Miniature art that tells an enormous story.

The Magical World of George Phar Legler.

A reproduction of earth's many biomes.

The 25th President's marble casket can be visited in this classical Ohio tomb.

Abandoned former poorhouse, bible college, and haunted house in an Ohio hamlet.