On top of Gibbet Hill lie the ruins of a lavish turn-of-the-century estate that never quite came to be.

This miniature feudal castle was built on a whim to honor a US Navy pioneer.

Naturally formed white marble arch housed in an abandoned marble quarry from the 1800s.

This small section of the Sleepy Hollow Cemetery is rotten with famous authors' graves.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

35,000 grape hyacinths flow like water down a garden hill.

Unlike other abandoned asylums this empty institution welcomes visitors, just don't go in the buildings.

Three prestigious academic collections come together to create a world-class natural history museum.

One of the most scenic falls in Massachusetts has a history of death and grim legend.

The inspiration for H.P. Lovecraft's horror stories and Batman's Arkham Asylum is now a condominium complex.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.

This nearly abandoned town was once a thriving mining community until a series of fires.

The remnants of the base where US Army troops learned how to fight in extreme conditions.

"All Mountains - All The Time."

This old train trestle and collapsed tunnel once allowed the railroad to negotiate the steep slopes of the Colorado Rockies.

Hidden high on a remote mountain peak is a humbling and mysterious Vietnam War memorial.

This three-mile concrete levee in Pueblo, Colorado was transformed into the world’s longest painting.

Each year, teams of the world's best snow sculptors have 65 hours to create frozen masterpieces.

16,500-acre ranch filled with American heritage, geological wonders, and a giant pile of tires is the crown jewel of an intriguing tug-of-war.

A coal fire has been burning underground here since 1896.

The site of the "Bone Wars" between two rival paleontologists during the dinosaur rush of the 19th century.

A river runs through this remote valley in a very unexpected way.

This once-popular otherworldly landscape was formed by one of the largest volcanic eruptions in history.