This brick-lined pedestrian walkway was once a railway tunnel used during the Civil War.

Art deco landmark on the outskirts of Washington, D.C.

Once the supplier for noteworthy projects like the National Cathedral, this old brickworks now lies abandoned.

The Corinthian columns that towered over Abraham Lincoln’s inauguration stand proud.

People escaping slavery may have hidden inside a corpse vault.

A historic ruin just 20 feet away from a busy highway onramp.

A historic neighborhood church is reborn as a psychedelic arts collective.

Operational for less than a year, this mill produced more than 11,000 tons of chrome concentrate in its short lifespan.

Standing for over 200 years, the abandoned home of a Revolutionary War hero and later a succession of prison superintendents.

Derelict buildings are all that remain of a complex at the site of one of the worst mining disasters in Montana history.

A decaying garage hidden amid the dense forest is all that remains of a once-prosperous dairy farm.

This former Cold War missile control site played an important role in the creation of GPS.

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

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

An out-of-place Air Force radar dome is all that denotes this park as a former missile launch site.

The most historic church in Fairfax County played a role in the creation of the American Red Cross.

The ruins of this long-abandoned unsuccessful gold mine can still be found.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

One of the oldest train stations still standing in Virginia played a vital role during the Civil War.

Burke’s oldest cemetery also houses the victim of the county's grisliest murder.

Look closely and you’ll notice that the color changes a third of the way up the tower.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

The "lovely red Vega" of the legendary record-settling pilot.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.