This iron and wood Civil War city-ship was the first vessel to be sunk by an electrically detonated torpedo.

The second-largest ceremonial mound in the United States is an artificial hill that is loosely shaped like a pentagon.

A grandiose octagonal home crowned by a large dome stands out among the antebellum mansions.

Giant novelty guitars now mark the spot where Robert Johnson is said to have sold his soul to the devil.

This racially troublesome eatery thought a new coat of paint could erase its offensive connotations.

An eerie and beautiful group of columns mark the site of a grand mansion lost to time and fire.

America's smallest "national forest" has only 33 trees.

This memorial pyramid marker honors one of the United States Government's first official camel riders.

After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

This immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

An old saloon in the West filled with history, and according to some, a few dozen ghosts.

The world's largest rose bush has literally outgrown the pioneer museum it was planted behind.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

The world's largest military aircraft cemetery.

What is the Thing?

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

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

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

A B-17 bomber stands as a memorial to the residents of Tulare County who served in World War II.

Thousands of turbines whir at at the origin of North American wind power.

These four islands right offshore have waterfalls, colorful lights, fancy buildings, and a secret purpose.

A chain of bells connect the California Missions and honor the legend of the "King’s Highway."

Etched into a dry lake bed, this massive directional indicator is accurate without magnets.

A decommissioned Naval base now rents itself out for people who want to blow stuff up.