The only gulag ever to exist in socialist Yugoslavia.

On the coast of Sardinia, a once-great mining village is finding new life as a coastal resort town.

This former luxury resort in Kaua'i is now an abandoned relic.

Abandoned medieval hill town.

Architectureal fantasy quarter of Rome.

This entire town moved to a safe location after it was devastated by an earthquake, but the remains of the original town are still around.

This centuries-old Italian chapel hangs midway down a sheer cliffside.

Medieval town turned hippie commune, once home to the secret foreskin of Jesus Christ.

An Italian hillside ghost town.

Vast network of air raid tunnels beneath Lombardy's capital.

These gutted monastery ruins still stand proudly in the middle of the Italian countryside.

On rare days, this abandoned castle's gatekeepers open its doors, revealing the eye-popping splendor hidden inside.

This medieval Italian town is a sheer (and beautiful) cliffside defense.

Venice's island of the dead.

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.

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

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

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

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

A beautiful, creepy 19th-century castle stands incongruous in rural Vermont.

137 graves holding New England's earliest residents.

An archival collection of over 2,200 case studies which includes human brain specimens and tumor specimens.