This colorful artistic feature atop a Danish art gallery allows visitors to stroll through a rainbow.

Copenhagen's celebrated theme park and gardens.

Ruins of two abandoned stations destroyed by the power they sought to harness.

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

Walk behind a 50-meter-high waterfall.

This "preacher's pulpit" once used for pagan ritual, is home to a new, and dangerous ritual.

Walk 2,300 feet above the ground on the "Troll's Tongue."

This Arctic mining town is home to a cat that's spent years masquerading as a fox.

This abandoned mining village was predicted to resist decay longer than any other modern human settlement.

This Norwegian satellite station provides ground services to more satellites than any other facility in the world.

In the northernmost city in the world, it's illegal to be buried because it’s too cold for bodies to decompose.

Cold storage for agricultural biodiversity.

The rusty hull of this 1899 ship serves as a tribute to explorers of the bottom of the world.

Despite being tiny and rural this Georgian airport looks like a sci-fi boondoggle.

A museum glorifying the life of Stalin, located in the city of his birth.

This architecturally eclectic fortress witnessed centuries of bloody turmoil, including the massacre of its ruling clan.

A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

You'll find just about anything in this funky Tbilisi flea market.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

Fortified homes of highland warriors that are still in use today.

Take respite inside this jaw-dropping church while climbing the volcano where Georgia's Prometheus was once chained.

Small church on top of a huge rock column.

These Stalin-era industrial 'death traps' hang lifeless above the city

Underground monastery and fortress.