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

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

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

Where the U.S. government kept its actual treasure, before Fort Knox.

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

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

Once the supplier for noteworthy projects like the National Cathedral, this old brickworks now lies abandoned.

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

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 traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

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

Perhaps the most scandalous statue of America's first president.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

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

The most accurate timepiece in the world.

The "lovely red Vega" of the legendary record-settling pilot.

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

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.

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

A celebrity from the late Cretaceous period.

Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

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