This prison on the Maltese island of Gozo is almost 500 years old, and they have the graffiti to prove it.

This subterranean necropolis holds three floors of antler-dug grave caves.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

This Stone Age solar temple aligns with the sun on each equinox and solstice.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Metro station with a claim to rock n' roll fame.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

An abandoned Byzantine fortress and notorious prison.

An ancient octagonal weather station named for the eight Greek gods of wind.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

A former factory serves as a shrine to the industry that sustained Santorini for decades.

Once the grandest synagogue in medieval Spain, it now stands as a memorial of the 15th-century Jewish exile.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

In one of the smallest countries in the world stands an original Salvador Dalí sculpture.

A New Zealand communications tower stands as the tallest structure in the Southern Hemisphere.

Handcrafted thermal spa washes away each night with the tide.

The platform atop this verdant volcano was built with the help of a royal elephant.

Major tourist destination known for its bubbling mud-pools and hot thermal springs.

The glacier tucked within a New Zealand rainforest.

This electric green sulphur lake in New Zealand looks like a cartoonish radioactive dump site.