This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

Giant busts of 42 U.S. presidents sit, crumbling in a field in Virginia.

An alternate history park where the Union Army loses the war... to dinosaurs.

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

One of the last active volcanoes on the Eastern seaboard.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

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

Outsider art meets paleontology at this roadside reptile repository.

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

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

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

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

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

The remains of a historic plantation nestled in between a parking lot and the rental car return at Reagan National Airport.

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

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

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

A former major munitions plant that has been converted into a sprawling art space.

An original apothecary from 1792.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

A memorial to a shareholder activist feared by CEOs around the United States.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.