The first blast furnace in the United States that used coal and coke fuel instead of charcoal to make pig iron.

An oft-overlooked, magically musical monolith that stands majestically between Arlington Cemetery and the Iwo Jima Memorial.

Despite violent work crews and massive delays this abandoned canal tunnel was built to last into the modern day.

This one-room cabin where the young colonel slept during the French and Indian War.

Maryland's first (and last standing) toll house on America's first federal road established the state as the "Gateway to the West."

The antique hotel still has a jail in the basement, though the cockfighting ring is long gone.

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

A remarkable time capsule of American manufacturing deep in Maryland coal country.

The highest point in Maryland is only accessible by hiking through another state.

This claimant to the title of "smallest church in the 48 states" doubles as an equally tiny, quasi-post office.

This hollow steel globe is the second-largest in the world.

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

Over the last century, this elegant columned facade has been home to the headquarters of a bank, several nightclubs, and a restaurant.

The ruins of an 18th-century mansion that was once named "Mistake" by the man who had it built.

The last vestige of a once substantial orchard and farm in the suburbs of Northern Virginia.

A nostalgic bibliographic gem.

A memorial to legendary newsman, publisher, and owner of La Gaceta, the only trilingual newspaper in the U.S.

This grand Spanish-Cuban restaurant has been serving customers for more than a century.

I-95's Tijuana-style celebration of kitsch at the Carolina border.

A home built with marble tombstones from the graves of 2,200 Union soldiers buried in a Virginia cemetery.

Art Deco urban decay at this historical building.

This woodland architectural installation acts as a camera obscura for the heavens.

A water pumping station disguised as a residential home to assuage concerned neighbors now tricks most passersby.

In a pedestrian tunnel on North Carolina State’s campus resides an expressive and artistic free-for-all.