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

This bell is one of the last remnants of the lost city of Triadelphia.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

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

The trials and tribulations of marking Poe's grave.

The Decoy Capital of the World.

A swimming hole in the historic industrial quarry that supplied the marble for the Baltimore Washington Monument.

America's first nuclear-powered merchant ship is now a time warp to the atomic age.

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

A mammoth pair of Civil War artillery guns abandoned out in the forest.

Historic home of America's sweetheart sharpshooter, Annie Oakley.

Electronic inventions that resulted in products and systems we use every day are on display in this labor-of-love museum.

The whole world in one water tank.

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

Politicians, bureaucrats, and military officers gathered in this field near the Capitol to settle their disputes with blood.

Live data is transmitted from the Atlantic coast to instantly recreate the ocean waves in this fountain at the NOAA headquarters.

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

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

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

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

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

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

Ship skeletons haunt Baltimore's waterways.