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

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.

The whole world in one water tank.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

Easter in Westminster may be the only time and place to behold Edgar Allen Poe made entirely of Marshmallow Peeps.

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.

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 remote horde of architectural treasures fit for Indiana Jones.

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

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

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

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

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

This simple convenience store sits on the location where the Ouija board was named—and has a plaque to prove it.

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.

A model home in the Medical Examiner's Office in which grisly death scenes are staged to train forensic investigators.

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

Ship skeletons haunt Baltimore's waterways.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

This abandoned Victorian-style house was built in 1884.