This collection of grinning ephemera has grown from basement to Brooklyn.

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

Plundered and left asunder by grave robbers, this ancient necropolis has been painstakingly pieced back together.

Popular tourist destination where witches in dark hats sell dried llama fetuses for good luck.

For centuries no one knew there were hundreds of bones and precious artwork hidden beneath this Swiss church.

The former estate of the Guggenheims, part of the opulent Gold Coast that inspired the Great Gatsby.

A millionaire's abandoned swimming pool from the gilded age of one of America's most distinguished families.

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

All that remains of a magnate's dream home is a historic gate and an abandoned public pool.

This abandoned factory on the Hudson River once churned out a million bricks a week.

An abandoned horticulture institute gloomily presides over rows of derelict and vine-wrought greenhouses.

This tiny church near Sleepy Hollow contains Henri Matisse's last work, a rose window, and nine windows by Marc Chagall.

A former connection to City Island, it has been abandoned since the 1930s.

The saddest little diner in New York.

This abandoned subway station can still be seen on regular commuter trips.

For over 30 years the walls of this Harlem schoolyard have been a gallery of street art by "Kings and better."

Bowl in splendor, if you're lucky.

The world's oldest hologram gallery and the labyrinthine laser laboratory of a holography pioneer.

The oldest surviving synagogue in New York City is now a soaring art space.

One of only two commuter aerial tramways in the United States.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

Try not to get slimed in Tribeca.

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