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

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

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.

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

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

Home to items never before seen by the public.

A brass and marble scale model of the solar system embedded in the concrete.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

This apartment building designed by a notable Washington D.C. architect housed the Qing Dynasty's Legation.

An amazing example of early-20th-century architecture, this church features marble transported from Utah.

The last remaining building in Washington, D.C., built by H.H. Richardson, one of America's most iconic architects.

Dedicated to the man who created the first radio wave communication system.

Where you can hail your favorite fictional commanders-in-chief.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

This statue of the "father of television" stands prominently in the United States Capitol.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.

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

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

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

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

A nostalgic bibliographic gem.

The national park was once a plantation estate.