Large Hadron Collider and the Birthplace of World Wide Web.

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

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

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

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

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

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

Northern Ireland's Brobdingnagian stepping stones.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

A museum marks and documents the site of the Titanic's launch.

The ship built to ferry passengers and goods to the doomed Titanic is now the last remaining White Star Line vessel.

An Irish cemetery filled with victims of political strife and violent conflict, including the grave of Bobby Sands.

The highest peak in Northern Ireland is topped with a stone tower and haunting burial mounds.

This massive blockhead sculpture hides an entire library.

The world's largest wooden structure.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

Commonly acknowledged as the only public monument to the Devil himself.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.