In the town of Åtvidaberg, the midday sun sets off a loud cannon boom.

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

One of the most breathtaking railways in Europe also takes one of the steepest climbs, from fjord to mountain plateau.

A thin pane of glass keeps visitors from sliding off this futuristic skywalk.

Monuments don't get much more metal than these three giant viking swords planted in a Nordic hill.

Walk behind a 50-meter-high waterfall.

A stunning silver lining to global warming's gloomy cloud.

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

A serpentine highway twists and turns over the treacherous Norwegian Sea.

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."

One thousand trees were planted in Norway to be used to print books a century from now.

Copenhagen's celebrated theme park and gardens.

The gilded, masterful astronomical clock will calculate time, dates, and planetary positions for thousands of years to come.

Opulence and fantasy collide in this royal chair which is supposedly made with unicorn horns.

This fantastical icy castle is built anew every winter.

A floating underwater hotel, created by a Swedish artist.

A palatial horse museum outside Shanghai is home to the most pampered horses in the world.

One of the largest bamboo bridges in Asia, located right next to a bamboo school.

A gigantic statue of a Russian soldier watches over the ancient city of Plovdiv, a prominent reminder of the Soviet period in Bulgaria.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

The site of the first battle of World War II.

The former 1920s mansion of a prominent Catalan developer was used as the Soviet Embassy during the Spanish Civil War, and there is still a bunker below the garden.

One of only two places in the world where two rivers cross each other without the waters mixing.