Seemingly unremarkable items like empty sushi trays, chef hats, and freshness stickers are being preserved so future generations can look back on this beloved cultural import.

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

A computer bug so primitive it was an actual insect.

There's a crumbling old mansion inside the Smithsonian National Zoo.

Largest Roman Catholic church in North America.

When it opened during the final years of the embargo, all the drinks and cigars were free.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

The national park was once a plantation estate.

An Industrial Revolution-era public work that purified water using nothing but sand.

The most decorated dog of World War I is preserved in the Smithsonian.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A derelict bit of transportation infrastructure hidden in the woods.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

A wondrous old library overlooking the nation's capital.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

A historic neighborhood church is reborn as a psychedelic arts collective.

Home to items never before seen by the public.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

This grand gothic brewery has been pumping out suds for over a hundred years.

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

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.