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

100 year tradition of fist fights, marked by marble footsteps.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

Budapest's Communist-era statues, banished to the suburbs.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A safari-themed castle in the South African bush with the largest maze in the southern hemisphere.

The world's highest and most dangerous infinity pool lies at the precipice of Victoria Falls.

This stunning concert hall has become a symbol of Iceland's national recovery.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

Three columns of volcanic rock shoot out of the ocean.

This elegant arc of a waterfall marks a religious turning point.

Climb right into the heart of this colorful Iceland volcano.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

Iceland's largest lagoon is home to stunning multi-colored icebergs.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.