This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

An overlooked memorial honoring the local Washington residents who died in World War I.

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

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

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

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

The rogue roots are gradually consuming some of the historic marble grave markers.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

Once the site of the Hawaiian monarchy, this building was originally designed as a palace.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

The 17th-century hacienda where Simón Bolívar spent his last days before dying from tuberculosis.

The colonial city's social history is reflected in its fanciful door knockers.

In the middle of one of South America's most historic walled cities lies a bar with an enormous collection of Soviet memorabilia.

This elegant Colombian fortress was one of the torture headquarters for the Spanish Inquisition.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

Glass and concrete building designed by Albert Kahn.

The birthplace of the Ford Model T is now a museum full of antique cars.

The concrete shell of an industry giant remains as a playground for graffiti artists, auto scrappers, and paintball warriors.

Controversial tribute to the heavyweight champion boxer who grew up in Detroit.

The world’s largest Masonic temple was saved by the White Stripes.

This public baseball field is a beloved remainder from of one of the most historic stadiums in the country.

A Beaux-Arts triumph set to become Ford's innovation campus

The only surviving prototype for Buckminster Fuller's house of the future.

Learn about the history and craftsmanship of carousels inside this museum located in a former post office.