Hidden for 165 years inside a building designed by Thomas Jefferson are the remains of what may be America's first educational chemistry lab.

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

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

Volcanic stone sentinels stand watch at a Korean Bell Garden in Virginia.

The rogue roots are gradually consuming some of the historic marble grave markers.

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

This grave marks the passing of a historic Jane Doe whose identity remains a mystery to this day.

This museum sits on the site of a decommissioned military communications base.

The Virginia home of one of the signers of the Declaration of Independence is being preserved with a unique glass facade.

An eight-sided home built during a brief octagon craze in the 1850s.

A "hospital" where people went to be quarantined, die, and be buried in the yard.

Collecting 700 years of mechanical death-dealing, the NRA's sprawling gun museum is a revealing testament to the American obsession with armament.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

The only place for a truly presidential dram.

Parking garage where Bob Woodward met Watergate source "Deep Throat."

The Grand Ole Opry's big voice came from a small home in rural Virginia where she was eventually buried.

This pre-Revolutionary War grist mill ground corn and flour for soldiers in seven American wars.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

At 207 feet, one of the world's longest continuous escalators.

The Virginia farm where John Wilkes Booth met his grisly end is now largely forgotten.

An extensive, if one-sided, history of U.S. law enforcement's war on drugs.

This war hero's old shop remembers the fine line between medicine and quackery during the Revolutionary War.

This unique historical monument features large concrete spheres designed to resemble fallen stars.

Take an otherworldly journey in a school dedicated to out-of-body experiences.