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

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

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

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

A historic arena where the Beatles played their first concert in the U.S.

The towering figures were created from the cemetery's fallen old-growth trees.

This grisly headstone doesn’t seem to be resting in peace.

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.

The oldest continuously operating fish market in the United States.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

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

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

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

The house where John Wilkes Booth conspired with his co-conspirators.

Giftshop catering to cryptozoologists and anyone with a sense of humor.

Home to items never before seen by the public.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

This unique historical monument features large concrete spheres designed to resemble fallen stars.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

At 207 feet, one of the world's longest continuous escalators.

The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

A wondrous old library overlooking the nation's capital.

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