Once the most densely populated place in the world, this island is now a ghost town.

These hellish-looking cliffs in the Canadian Arctic have been burning for centuries.

The closest thing to Mars on Earth.

Remote and wild, Kinnarodden is the northernmost point of mainland Europe.

At the very tippity-top of Europe is a cliff from which you can view the midnight sun.

Norwegian explorer Roald Amundsen's airship docked here before leading the first-ever flight over the North Pole.

This cairn marks the only place where Central European Time, Eastern European Time, and Further-eastern European Time meet.

These 4,444 wooden steps straight up a mountain were built to serve a hydroelectric power station but these days, they're mostly used by hikers.

This giant boulder is pinched over a 1000-meter abyss by two mountains.

This Swedish automobile graveyard is a beautiful gallery of decay, but woe be to any who would steal a souvenir.

This network of conjoined cellars was riddled with traps and supposedly allowed the townspeople to pretend their homes were deserted.

The deepest sinkhole in Central Europe comes with a grisly tale and an unusual nickname: “The Stepmother Abyss.”

A trio of giant wooden megaphones turn up nature's volume in this Estonian forest.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

"World machine" built by an untrained Austrian farmer.

This cubist Vienna church building looks like some sort of alien stonehenge.

A spherical "micro-nation" in the heart of Vienna.

Handsomely crafted representations of our round planet.

This unique structure allowed boats to bypass underwater mine barriers in the channel to enter the harbor.

Over 40 species of fern cover the canyon walls of this lush green bowl, cut off from the bustle of the world by a cave entrance.

These caves are home to a small church and were used to age cheese.

A monument to Poland's famous alleged UFO abduction case.

The oldest wind turbine in Europe, constructed by a group of friends in 1932.

Built to transport German U-boats through the never-completed Masurian Canal, the locks near this Polish village are now home to a rope course.