An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

The U.S. Navy’s preposterously detailed mini battleship took 77,000 hours to complete.

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

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

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

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

A diminutive plaque recalls the treetop sniper who almost killed Abe Lincoln.

A historic arena where the Beatles played their first concert in the U.S.

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

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

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

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

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

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.

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

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The most accurate timepiece in the world.

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

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

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.

An obscure public service from the U.S. government that redeems burnt, moldy, and soiled old greenbacks.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

A nostalgic bibliographic gem.

The oldest continuously operating fish market in the United States.