This unassuming passageway played a key role in one of the most important events in U.S. history.

Daily lunch spot for many of Washington, D.C.'s cab drivers.

The world's oldest soul food restaurant is also one of its best.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

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

This poor little statue is the most vandalized memorial in Washington.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

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.

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

A computer bug so primitive it was an actual insect.

Home to a vast and influential collection of Shakespeareana.

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

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

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

The walls of the iconic dome are hollow and have a secret stairway.

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

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

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

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

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

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

Micro-nation based around a nine-story high illegally built tower.