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

This war hero's old shop remembers the fine line between medicine and quackery during the Revolutionary War.

A convincing little bit of ancient Egypt smack dab in Richmond, Virginia.

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

This statue is dedicated to Grace Sherwood, the last person in Virginia to be convicted of being a witch.

The narrowest house in America is seven feet of pure spite.

This Virginia railway overpass is said to be haunted by a serial killer in a rabbit costume.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

Two statues of the fictitious toy robots that ran afoul of local government

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

National Mall monument to the inventor of the screw propeller.

A centuries-old stone pagoda from Japan stands among cherry trees beside the National Mall Tidal Basin.

A small park honors the legendary Ukrainian poet.

This American Civil War-era fort still stands near the border between Washington, D.C. and Maryland.

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

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

A spectacular tribute to statesman and philanthropist Andrew Mellon.

This historic boathouse was constructed using salvaged lumber from burned barns.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

The hippo that stands on this university campus was once a drunken flea market purchase.

The Lincoln Memorial has inspired many, even though a word on the inscription appears to be spelled incorrectly.

A gift from Japan, 17th-century lantern stands among the cherry trees at D.C.'s Tidal Basin.

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