100 years later, they're still down there.

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

A historic neighborhood church is reborn as a psychedelic arts collective.

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

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

A nostalgic bibliographic gem.

Home to a vast and influential collection of Shakespeareana.

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.

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

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

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

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

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

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

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

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