The only Leonardo Da Vinci painting in the Western Hemisphere.

Now a living classroom, this house was once the home of Reverend James Clinton Dent, a formerly enslaved man and a pastor.

Sip creative cocktails in the former vault of the Riggs Bank.

Press 1 for knock-knock jokes.

A surprising, but overlooked example of geology in the middle of the nation’s capital.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

The United States Capitol's former columns still stand.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

A terrific purveyor of natural history objects and curios.

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.

The only place for a truly presidential dram.

The only recreation of William Shakespeare's indoor playhouse.

Bubbling up from deep underground is the warm crystal clear water that fills the Warm Springs Pools, America's oldest spa.

An original apothecary from 1792.

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

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

Outsider art meets paleontology at this roadside reptile repository.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

The district's only illusionarium supports free writing programs for local students with every purchase.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.

The span is crooked and made from two older recycled bridges.

This leafy estate is worth $18 million and is so grand it has two mailing addresses.