The inventor of a number of hybrid corn species is immortalized with a field of giant corn.

The world-record holder for the longest bridge stretching continuously over water.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

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

An overlooked memorial honoring the local Washington residents who died in World War I.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

Look closely and you’ll notice that the color changes a third of the way up the tower.

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

Washington's iconic carousel has a nice piece of Civil Rights history.

The most accurate timepiece in the world.

Decades before the scandal, this staircase on the river was a literal "water gate."

The hidden offices underneath Memorial Bridge have been locked up since 1976.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

One New Hampshire alleyway has become home to a public gallery of feline art.

A tunnel of hardened lava along Maui’s famous Road to Hana.

A precariously balanced rock perches on the edge of a cliff created tens of thousands of years ago by glacial erosion.

World's first "penitentiary," meant to be humane, drove men insane.

One of the largest, oldest, darkest, quietest motel rooms in the world.

A museum dedicated to exhibiting remarkable outsider art.

The land is home to swimming ponies and a legendary 18th-century treasure.

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

An FDR-era tuberculosis sanatorium has stood abandoned in the suburbs of the U.S. capital for over 30 years.

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.