The bad-ass ride of a soul legend, housed in one of the world's few soul museums.

One of the foremost Sherlock Holmes collections is hidden away at a Toronto library.

This "Palace of Purification" has made many film appearances as a dark and sinister headquarters.

The stunning interior of this Gothic church is covered in ornate gold details.

Europe's largest collection of matchbox designs is a fascinating exploration of the cultural history of the world.

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

Home to a vast and influential collection of Shakespeareana.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

A portal into the bricked up canal that runs through the heart of Washington D.C.

This nine-story building is the oldest standing skyscraper in D.C.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

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

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

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

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

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

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

The national park was once a plantation estate.

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

The most accurate timepiece in the world.

The oldest continuously operating fish market in the United States.

The "lovely red Vega" of the legendary record-settling pilot.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.