Relics of Australia's convict past, and a modern scene of unimaginable horror.

Celebrated as a center of civilization, the remains of the ancient city have been nearly destroyed by greed, egoism, and war.

Stone Age solar temple is aligned with the sun on each equinox and solstice.

The bomb-ravaged remains of of a colossal Neptune.

The world's largest military aircraft cemetery.

Underground monastery and fortress.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Virgil's many-mouthed gateway to the underworld.

Once the path of a railway tunnel, now home to thousands of glowing insects.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

Rome's ancient Etruscan rival, now a park full of ruins.

A Turkish ghost town abandoned in a population exchange with Greece.

An ancient Thracian city where fire rituals were practiced on the largest cult altar in Southeast Europe.

A village on the east coast of England that has almost completely eroded into the North Sea.

Mysterious Spanish catacombs of unknown origins.

An outsider folly near Madrid.

An ancient Egyptian temple in the middle of Madrid, Spain.

Ruins of a German Castle on top of a towering stone pillar.

These Nubian pyramids are strange and unique, even by pyramid standards.

More than 100 monumental tombs carved into rock are preserved at this ancient Nabataean site in the Arabian Desert.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

Enormous statue of the Emperor of the Mongols.