This sprawling farm was once a Cold War-era hideaway for the nation's top diplomats.

Please don’t anchor your boat onto the Department of Defense’s underwater data cables.

The Pentagon sits on a former island that was in Virginia at low tide and D.C. at high tide.

This church is known as "The Home Church of George Washington and George Mason."

A massive, majestic mammal watches over pedestrians from his perch atop a former B.P.O.E. lodge.

The former home of the man whose radical ideas changed the nation.

This little brick tunnel built by Confederate forces was used to conduct surprise attacks on the railroad.

Originally dubbed "Retirement" by the Navy Commodore who built it in 1780, this beautiful mansion is now the centerpiece of a suburban community park.

This cannon dating to 1755 has stood guard at this suburban intersection since 1915.

This pharmacist and his patient greet visitors to the National Community Pharmacists Association.

Long buried under the 20th-century landscape, this lift lock of the Alexandria Canal is the lone remnant of an ambitious early American transportation project.

A weathered, American Foursquare-style house originally built for lumber merchant William Wimsatt.

Get up close and personal at this Fresnel Lens.

Taste the white whiskey that the United States' first president once distilled and enjoyed.

This small pedestal marks the spot of the first lot of land sold in Alexandria, Virginia in 1749.

One of the Treasury Building's original columns now sits as a garden monument in the middle of a busy military base.

This pun was simply waiting to come to life, and one defense contractor made it so.

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 stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

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.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Giant busts of 42 U.S. presidents are sitting in a field in Virginia.

A small chapel celebrating the spiritual bond between dogs and humans.