Contrary to what one might expect, ice forms inside this small cavern during the summer and melts during the winter.

Quite possibly the last cross all humans will ever see.

Toxic waste disaster that founded the Superfund program.

A forsaken wonder in the middle of the East Side neighborhood.

This sprawling collection of saintly relics includes such fascinations as wood from the Cross of Jesus and threads from Mary's veil.

An abandoned asylum where patients have been forgotten but their possessions remain.

World's largest herd of white deer populate a former U.S. Army depot.

A natural gas leak provides a flickering flame beneath a waterfall.

An unassuming nature trail winds through dozens of tiny houses built for the wee people.

The site of a tragic massacre that spawned a multimedia franchise.

Protecting the future of some of the rarest and most misunderstood mammals of North America.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

A legendary speakeasy bookstore returns from the brink.

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

Cryptic messages embedded in the New York City sidewalk.

A terrific purveyor of natural history objects and curios.

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

Renaissance villa and gardens complete with a tormented colossus.

The remains of a town so thoroughly destroyed by French forces that the citizens simply left.

Geothermal waterfalls in Tuscany.

A 16th-century horror show built in a lovely Italian garden.

This picturesque Umbrian city has a subterranean side that has long remained hidden.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Discovered by cows, these upstate New York show caves are presented with a healthy dose of psychedelic folk art.