Bizarre Cavern.

This propitious plastic porcine has been petitioning park visitors to pick up after themselves for more than 50 years.

The ruins of this long-abandoned unsuccessful gold mine can still be found.

This massive swimming pool is the high tech home to the human-powered submarine races.

Tiny observatory made big contributions to the study of the Earth's motion.

The final resting place of the tragic king and queen of the Jazz Age is tucked away in a small Maryland graveyard.

Dogs, cats, horses, monkeys, frogs, and fish are laid to rest at the second-oldest pet cemetery in the U.S.

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

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

A local farm's collection of unusual structures from a now defunct storybook amusement park.

An eerie, decaying ghost town destined to fade into the forest.

Remnants of a storybook amusement park hidden behind a strip mall.

A priceless collection of the Nation's cryptologic history.

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

A remote horde of architectural treasures fit for Indiana Jones.

A quick journey through the history of Annapolis.

The development and impact of electronic media showcased in a picturesque farmhouse in Maryland.

An isolated island home to one of the oldest English-speaking communities in the region and Maryland's state dessert.

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

A state park that once served as an important river crossing, and now offers protected lands for endangered plants and animals.

The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

The rock on which Moll Dyer was found frozen to death is said to still bear her handprint.

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

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