Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Cairns built to bring travelers good luck stretch across the land like miniature stone mountains.

This beautiful, historic church looks like something out of a simpler past.

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

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

The summer tourists on these cliffs are thousands of seabirds.

A formerly glacier-tipped volcano that inspired none other than Jules Verne.

This mountain fissure hides a secret path to a secluded mossy grotto within the rock itself.

Strange rock formations tower above the river that snakes through this enchanting Icelandic canyon.

Three columns of volcanic rock shoot out of the ocean.

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.

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

Walk in the footsteps of the gods and straddle two tectonic plates.

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

Rising from the sea like a stone monster.

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.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

Physicist’s epitaph provides final confirmation to a career of turmoil.

Museum devoted to the artificial language of Esperanto.

The solemn exterior conceals an opulent interior of this 17th century church.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.