A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

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

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

The seat of the lost Ryukyu Kingdom has survived numerous fires and wars over the centuries.

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

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

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

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

The oldest Roman lighthouse still in use.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

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

Outsider art meets paleontology at this roadside reptile repository.

An eponymous directional signpost erected by the first president of the United States.

A whopping 14,000 copper coins cover this miniature fighter jet.

This monument traces the segregation line that inspired the first rural branch of the NAACP.

Eighty million natural history specimens call this gargantuan museum home.

As the glaciers retreated out of northern Wisconsin, this unique natural wonder was crafted.

This park harkens back to frontier life in Wisconsin.

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

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

The tragic death of 19-year-old Mabel Tainter in 1886 led to the construction of this unique Victorian-era theater in the northern woods of Wisconsin.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

The world's tallest aluminum statue is also the world's tallest image of a winged Virgin Mary.

An astounding collection of medical specimens, including bits of President Lincoln.