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

Historical figures from New York City's Catholic community reside in Midtown.

The last remnants of what was once one of the world's grandest hotels can now be found in a Manhattan subway station.

One of the oldest Jewish cemeteries in the city, it is now overgrown with an urban forest.

"A hideous albatross in the Hudson River Valley."

This Dutch Colonial home is the oldest remaining farmhouse in Manhattan.

One of only two remaining Victorian-era greenhouses in New York.

This old cement mine has been used as everything from a mushroom farm to a recording studio.

A Manhattan Episcopal church with an eerie underground crypt.

Relics given to a Manhattan church to avoid seizure by the Italian government.

A Victorian cemetery in the heart of Brooklyn remains a popular mecca of morbid curiosity.

A ruined mansion hidden in the woods of the Hudson Valley, home of a tragically doomed romance.

What was once a trend-setting, phrase-coining icon of architectural splendor is now a rotting, forgotten hulk.

Reclaimed by nature, the ruins of Doodletown, New York are remnants of a town consumed by a state park.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.

One man's swirling six-acre monument of stone.

This hidden library of physiological ephemera contains centuries worth of knowledge on the vim and viscera of the human body.

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

The oldest house in Manhattan is now a museum that remembers the home's sordid history of scandals, vice-presidents, and ghosts.

One of the best collections of wax anatomical models in the world.