An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

Elevated freight railway turned wildly successful urban park.

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

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

An enormous, inside-out glass globe built in 1935.

A toxic ghost town sitting atop a massive coal fire.

The oldest bibliophilia club in America, with exhibitions on historic books and graphic arts.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

World's first "penitentiary," meant to be humane, drove men insane.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

An artsy hidden staircase leads to breathtaking views of San Francisco.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

A terrific purveyor of natural history objects and curios.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

One-time largest man-made structure in the world will be a park in 30 years.

This stone tower marks a lookout point over the historic Washington Crossing, and maybe some buried treasure.

One of the world's largest model railroads is a mind-boggling achievement.

The highest point in New Jersey is marked by a massive, if simply named, obelisk.