Hot springs monkey spa in the middle of Hell's Valley.

An exquisite tunnel of cascading flowers.

A quaint Russian village in the middle of a German metropolis.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

This classic restaurant features a gorgeous mirror-clad room.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

The final resting place of many of Germany's most famous communists.

One of downtown Berlin's last reminders of its Communist past.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

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

Buried next to Pompeii, this lesser-known Roman villa was the opulent vacation home of Emperor Nero's wife.

This cliff-face port is considered a masterpiece of mining engineering.

This overgrown mountain village has been abandoned for nearly a century.

The sunlight passing through the opening of this huge cave system creates a magical effect.

This medieval hilltop village was abandoned at the end of the 19th century, after existing for more than 500 years.

This church carved into the rocks is full of enchanting stone statues.

A forgotten "city of water" underneath the famous Trevi district.

Amalfi's pre-industrial history is slowly being engulfed by the lush vegetation of the Ferriere Valley.

The world's largest bamboo labyrinth is a living demonstration of the plant’s immense potential.

Largest necropolis in the Mediterranean.

Behind medieval walls in a corner of bustling Palermo is a breathtaking former mosque once inhabited by a wolf-taming hermit.

The burial place of an obscure North African saint was turned into a macabre body preservation factory for the 17th-century Neapolitan elite.

Naturally preserved bodies are eerily staged throughout the crypt in varying poses.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.