This environmental engineering marvel keeps salt water from the Elizabeth River.

In what is rumored to be an intentional act of spite, this memorial almost completely obscures the nearby grave of a senior officer.

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

The Pentagon is so large that it was planned like a city, complete with internal highway infrastructure.

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

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.

The only surviving 19th-century water-powered mill found in the Washington, D.C. area.

Country fans may flock to Nashville's music scene, but this Appalachian town is where the genre was born.

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

Born a slave on the Arlington estate, Parks dug the first graves at Arlington National Cemetery, and was buried there, too.

A 100-foot metal tower and swinging bridge that provides stunning views of mountains in five states.

The airport was once a Civil War battleground, and the earthwork defenses can still be seen today.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

The romance of early commercial flight still fills this Art Deco destination.

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

The story behind the mysterious symbol painted in front of the historic university's famous Rotunda.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

This historic, one-acre island is the only legal place to camp in the city of Richmond.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

Scenic mount trashmore, Virginia Beach's most curious waterfront still has a couple of secrets.

Metal dinosaurs lurk in a sculpture garden on the outskirts of a popular resort town.

This cannonball stands as a reminder of the final act of a fleeting governor amidst a revolution.