For hundreds of years, automatons moving to metallic music have been marking the passage of time.

An underground paleo-Christian burial site composed of the remains of several cemeteries and Basilicas.

Bohemian paradise covered in majestic forests.

Ruins of a once-prized railroad station in New York.

This ancient Spanish castle sits high upon a hilltop.

Rock-cut caves and 7,000 Buddhist sculptures carved into the nearly sheer face of a sandstone mountain.

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

Gigantic unfinished stupa and the world's 2nd largest bell.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.

Astronomical observatory above Lake Titicaca.

Village of slate houses, built on a white marble outcrop.

200-foot-high minaret and only remnant of Afghanistan's lost city of the Turquoise Mountain.

15 monolithic temples emulate an eroding sand castle.

Abandoned Nazi train station turned underground astroparticle laboratory.

This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

Wonderland replication in progress by one persistent man.

At the foot of a waterfall lies a peaceful swimming lagoon and evidence of over 60,000 years of human habitation.

A beautiful oasis town dating back to the Roman period still serves as reprieve from the brutal summer sun in Libya.

This complex of vertically-excavated Buddhist, Jain, and Hindu monolithic temples in India's Maharashtra providence illustrates a spirit of tolerance characteristic of ancient India.

Highly unusual subterranean stupa and adjacent cave monastery.

The second-longest continuous wall on the planet protects a hidden secret in the deserts of India.

Island, once a pirate hideout, now home to an abandoned resort.

Keshwa chaca, among the last handwoven Incan bridges, crosses Apurimac Canyon in Peru.