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

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

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

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

The national park was once a plantation estate.

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

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

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

It was once the base for a series of domestic terror attacks.

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 famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

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

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

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

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

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

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

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

Home to items never before seen by the public.

The United States Capitol's former columns still stand.

The site of the climactic scene from the classic horror film is now a historic landmark.

Once a black market electronics marketplace, now an otaku shopper's paradise.