Medicinal spa created from the mineral-rich runoff of a geothermal power plant

Puffin enthusiasts flock to Europe's largest seabird cliff, which over one million birds call home.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

Bridge that died in war and was resurected.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

Gargantuan home of Russian science.

The tallest hotel in Europe.

A Gothic cathedral created from volcanic rocks.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

World's largest bell sits on the grounds of the Kremlin in Moscow.

Ancient burial grounds of the wealthy.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

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

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.

Romania's triumphal arch looks out over Bucharest.

One of the most remote and isolated villages on the Arabian Peninsula.

Stunning Roman aqueduct used for 1900 years and still standing.

Mediterranean castle on a tiny Turkish island.

3,000 market stands in five former Zeppelin hangars.

What happens when you cross a mayor and a painter?

Cliffside houses provide a spectacular view from their perch above the valley.

Famously misunderstood wonder of the ancient world

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

Go inside to really appreciate this 500-year-old technological masterpiece.