Three abandoned missile silos are hiding in plain sight behind a suburban development in Maryland.

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

This 1830s store is believed to be the site of Harriet Tubman's first stand.

This ruined quarry once produced the distinctive red sandstone used for construction projects in Washington, D.C.

Fascinating museum dedicated to the under-appreciated medical history of urology features some wince-inducing devices.

One of the oldest anatomical theaters in the U.S. still in use was once the site of an infamous cadaver riot.

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

Brain collection and database that narrows the gap between man and animal.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.

George Washington's dentures and Queen Victoria's dental instruments are in the nation’s official museum of the dental profession.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

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

A remote horde of architectural treasures fit for Indiana Jones.

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

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

This scenic Maryland park was the site of one of the worst prison camps of the Civil War.

A Civil War Museum with some notable medical antiques.

A haunting exhibit in a wildlife refuge center highlights threatened species and the conservation efforts needed to save them.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

This abandoned sea fort has become an accidental bird sanctuary.

After hundreds of years of settlement, this once-bustling fishing village sunk into the Chesapeake Bay.

An abandoned church gets a second life as a massive beer hall and event space.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

An eerie, abandoned military base engulfed by nature and graffiti is now home to a local park.