One person’s lost luggage is another person’s treasure.

The national park was once a plantation estate.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

Before Nixon, "watergate" meant canals.

People escaping slavery may have hidden inside a corpse vault.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

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

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

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

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

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

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 unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

Need a hardcopy of the 50-title Code of Federal Regulations? This is the place.

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

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

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

America's original house of worship for Spiritualism, the religious movement based on communing with the dead.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

Radical Bookstore and Community Space.

An enormous, inside-out glass globe built in 1935.

The world's third-largest scale model of the planets.

The crown jewel of the Queens Museum is a nearly 10,000-square-foot architectural model of the city originally built for the 1964 World's Fair.