For over 70 years, this house was home to a pioneering Black artist and educator.

The Conduit Road Schoolhouse is one of the last one-room schoolhouses remaining in Washington, D.C.

One of the first Second Empire-style buildings constructed in North America.

A spectacular tribute to statesman and philanthropist Andrew Mellon.

The story behind this beloved toy—named for Theodore Roosevelt and owned by his grandson—is more complicated than you might guess.

Depending on who you ask, this controversial treehouse is either a charmingly creative child's playhouse or an illegal encroachment on public land.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

The word "Watergate" will forever be associated with the infamous scandal in 1972, but this fountain is famous in its own right.

Once a sewer culvert, this road tunnel now offers cyclists and pedestrians a subterranean stroll under the C&O Canal.

A portal into the bricked up canal that runs through the heart of Washington D.C.

A public art jibe at one of the United States’ oldest and longest-serving senators.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

Before Nixon, "watergate" meant canals.

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

A super-sized promotional trick that is now a D.C. landmark.

The first custom-designed building to showcase the works of Dale Chihuly is a wonderland of glass and light.

Owned by Native American women, this brewery is a celebration of indigenous culture in the American Southwest.

These beautiful garden buildings are among the oldest surviving greenhouses in the United States.

A Civil War fort in the middle of Washington, D.C. has been swallowed by a forest.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

Press 1 for knock-knock jokes.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.