Space-age monument to an early 20th-century uprising.

A stairway to heaven, or to nowhere at all.

This "flat geyser" bubbles up out of the ground periodically like a disappearing river.

A study of Fascist era Art Deco design in Italy.

The NASA scientists behind Apollo 11 started out developing Nazi weapons at this abandoned German rocket factory.

Ancient structures used to make and preserve ice in the deserts of Persia.

The world's northernmost ice hotel.

An alien landscape on the banks of the Aegean Sea.

An artistic tribute to the famous singer, just around the corner from where he was born.

These abandoned coal mine towers near Sherwood Forest might soon boast the U.K.’s longest zip-line.

This stretch of the River Severn where large waves flow against the current is the birthplace of river surfing.

This renaissance château was home to an infamous witch hunter who sent a hundred suspected witches to their deaths.

This beautiful eden was once the vacation home of Tahitian royals before Marlon Brando bought it.

This tiny, charming synagogue in the Cayman Islands was built by a man as a present for his Jewish wife.

A turquoise lake within a volcanic crater.

For one day every month Barcelona's Estació de França transforms into a market for model trains.

This 16th-century monastery has been turned into a surrealist architecture compound.

The world's longest and deepest train tunnel.

The jaw of one of humankind's earliest ancestors on display at an overlooked geology museum.

No one knows who's responsible for decorating this tunnel with stuffed animals, but the people love it enough to protest their removal.

Travel deep inside of Europe's second largest glacier in the world's largest man-made ice cave.

Two volcanic lakes in an enormous crater formed in a prehistoric eruption.

A collection of art from Bulgaria's time as a communist state.

This salt marsh in Southern France is as pink as the flamingos that inhabit it.