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.

Tubing through a cave lit with glowworms is a magical underground experience.

The real life Hobbiton, this sheep farm has been forever transformed since being built for The Hobbit film series.

Come for the flowers, stay for the bats!

The maze-like transportation hub contains abandoned areas, derelict stores, and a resident bat colony.

Sofia's legislative center is continuously reinventing itself.

A vast Communist-era exhibition space in the Bulgarian capital.

A striking symbol of the Bulgarian capital.

This historic black and white monastery is one of Bulgaria's architectural jewels.

Dozens of elegant ceramic tiles decorate these ancient walls, each displaying the Lord's Prayer in a different language.