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

A promising candidate for the lost rock laid by George Washington was unearthed, but the hunt is still on.

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

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

In the basement of the U.S. Capitol Building is a hidden storage room full of ornate floor tiles leftover from the 1850s.

Senators used to relax in the nearly forgotten marble tubs now hidden in the U.S. Capitol Building's basement.

The elevator that makes it possible to fly American flags in bulk over the U.S. Capitol

Corn-inthian columns with a uniquely American take on neoclassical architecture.

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

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

During Prohibition, the U.S. Congress had an "official" bootlegger, with his own Capitol Hill office.

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

A secret greenspace hides atop a Capitol parking garage.

100 years later, they're still down there.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

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

A nostalgic bibliographic gem.

This groundbreaking 16th-century map is known as "America's birth certificate."

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.

There just so happens to be a court even higher than the U.S Supreme Court: a basketball court in the building itself.

Home to a vast and influential collection of Shakespeareana.

The tunnel under the Capitol Building where Congress takes out its trash.

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

After his presidency, George Washington planned to live only a few blocks from the Capitol building.