This shale formation along the Appalachian Trail once inspired the third president of the United States.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

This advertisement for talcum powder was painted on the rock face and has since defied removal.

A lone historical marker off the highway and scattered debris are all that remain of this Cold War-era missile site.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

The Kirkland Monument remembers a selfless Civil War hero who braved the battlefield to give water to his dying enemies.

A home that witnessed Civil War combat on the Sunken Road has the battle scars to prove it.

At Brandy Station, Civil War soldiers left their mark on the battlefield and the walls of this small wooden house.

A graveyard that dates back over 200 years stands near a busy shopping center.

New York City's smallest piece of private property.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

An unexpected Easter egg lurks in the background of a cherub wall relief at the Breakers mansion.

The only U.S. Senator to die on the field of battle is buried in San Francisco but memorialized at Balls Bluff Regional Park.

These unusual rooms on wheels are holdovers from the 1960s.