Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

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

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

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

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.

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

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

A celebrity from the late Cretaceous period.

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.

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

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.

A super-sized promotional trick that is now a D.C. landmark.

The oldest continuously operating fish market in the United States.

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

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

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

A nostalgic bibliographic gem.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

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

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

A painfully obvious spy house sits right across the street from the Russian Embassy.