This tumultuous Icelandic lava field looks so alien European researchers want to use it as a stand-in for Mars.

These ominous lava formations were said to be an entrance to the netherworld so of course they inspired a famous metal band.

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

The oldest steel ship in Iceland has been beached for years and is now a rusting ruin.

This collection of unique liquids allows visitors to wander the waters of Iceland's glaciers.

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.

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

Medicinal spa created with the discharge from a geothermal energy plant.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

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

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

The world's largest reflecting pool is just two centimeters deep.

Massive puppet-automaton machines created by French artist collective Machines de l’Ile.

Historic medieval fortified city in southwest France.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Just outside of Nairobi lies a large estate surrounded by endangered Rothschild giraffes, who have been fed from the window by Mick Jagger and Walter Cronkite.

Formerly known as the Malay Quarter, Bo Kaap is a colorfully-painted suburb located in the “Mother City” of South Africa.

Napoleon’s home in exile, decorated with poisonous wallpaper.