This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

An allegorical sculpture in Maryland wears the artist’s politics on its trunk.

The only surviving 19th-century water-powered mill found in the Washington, D.C. area.

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

This golfball sized platinum iridium cylinder is the official starting point for all national weight calibrations

Standing for over 200 years, the abandoned home of a Revolutionary War hero and later a succession of prison superintendents.

Designed by Horace Trumbauer in 1893, this Gothic-style castle is now a home for academics.

This stunning home looks like it belongs in medieval Europe, not North Carolina.

This Scottish manor house is a lush relic from the life of a literary great.

This Connecticut chapel is a starkly modern, and surprisingly colorful, architectural rebel.

An iconic steel and chrome diner from the 1940s left empty for nearly 20 years is in danger of being demolished.

An abandoned asylum once on the cutting edge of lobotomies may be reborn as a Christian college.

Collection of trolley cars in the woods represent one man's attempt to preserve transportation history.

The remains of a century-old mansion that met a fiery demise years after it was deserted.

A historic recreation of the golden age of the Erie Canal, abandoned for some time, slowly being restored.

The abandoned ruins of America's first private zoo are open for exploration in the Catskills.

Hundreds of numbered stakes hidden in the woods mark the graves of the lost souls of a nearby asylum.

Decades after testing the polio vaccine on unwitting patients, this historic mental hospital sits in ruin.

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

This mouldering abandoned mental hospital was once a center for progressive healing.

This little-known Revolutionary War fort is supposedly haunted by the ghosts of its past.

North America's oldest quarantine facility was built in response to Philadelphia's 1793 yellow fever outbreak.

Ruins of a historic medical facility sits eerily by the water.

An abandoned tuberculosis hospital moulders on into an uncertain future.