This former asylum for Black Americans is haunted by its history of violence and racism.

A star fort along the C&O Canal in western Maryland that protected America in three wars.

The whole world in one water tank.

A labor of love built by local hang-gliding enthusiasts, this ideal launch spot was outlawed by the authorities and has since been largely abandoned.

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.

A Civil War Museum with some notable medical antiques.

Built by the patriotic residents of Boonsboro in a single day.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

This beloved Baltimore spot features caged dolls, a giant Pez collection, and many, many mannequins.

Bizarre Cavern.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

A snapshot of the city's fascinating voodoo culture.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

World's first "penitentiary," meant to be humane, drove men insane.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

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

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

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

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

Home to items never before seen by the public.

Through the decades, Black music stars have performed at this historic hub for music and the arts.