Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

From scholastic to sepulchral - now under reconstruction.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

The saddest little diner in New York.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

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

Elevated freight railway turned wildly successful urban park.

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

This was one of the first (and last) university-built and operated nuclear reactors.

Haven for steampunks.

The largest cave shaft in the world is home to thousands of birds and popular with BASE jumpers.

This hospital fell into ruins after failing to act as the advocate for the mentally ill it was designed to be.

Oslo's historic toboggan run has been letting thrill seekers slide from train stop to train stop for over a century.

Tropical paradise strewn with hundreds of World War II wrecks.

The ruins of an ancient island city built atop a coral reef in the South Pacific are spectacular and strange enough to have inspired H.P. Lovecraft.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

Series of storm drains connected to a dark urban legend.