A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

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

There’s a special club house at the top for the bell ringers.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

A fantastic array of trays and cables once whisked books over to the Capitol at 600 feet per minute.

Art deco landmark on the outskirts of Washington, D.C.

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

The towering figures were created from the cemetery's fallen old-growth trees.

A clone of a cloned tree that was so important it allegedly had its own guards.

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

In the basement of the U.S. Capitol Building is a hidden storage room full of ornate floor tiles leftover from the 1850s.

Go take a picture with the inventor of the daguerreotype photographic process.

The first presidential bomb shelter was located in an old vault under the Treasury, connected to the White House via tunnel.

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

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

This lovely pocket park is one of the most under appreciated in D.C.

A brass plaque dedicated to a convicted cannibal hangs in the National Press Club, and that's not even the craziest part of the story.

Obscure Freemasons still live in D.C.’s largest private residence.

A historic ruin just 20 feet away from a busy highway onramp.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.