When flour explodes, it's not a pretty sight.

20,000 pieces in a Frank Gehry-designed building.

The only arched bridge made of stone on the entire Mississippi River.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

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

A modern Nordic Pompeii on the Icelandic island of Heimaey.

The most powerful waterfall in all of Europe.

Small Island off the coast of Greenland.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

The "Crow Boat" of Kootenay Lake, sold for a dollar and now on display as "the world's oldest intact passenger sternwheeler."

Fossils, railroads, and waterfalls!

Few other hotels can rival the grandeur of the Castle in the Rockies.

Famously misunderstood wonder of the ancient world

Largest lake in Great Britain measured by surface area.

This historic observatory contains the world's oldest refracting lens telescope.

This trio of Australian rock spires may have inspired aboriginal legend or just modern tourism.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Megachurch turned Catholic church comprised of 10,000 glass panes.

Oldest building in California still in use.

The world's longest outdoor covered escalator system transports commuters through Hong Kong's hilly terrain.

Stained glass windows bathe this botanical garden in cosmic light.

The only castle in North America to ever house European sovereigns.

This was once the center of the Birdman cult, and is now a World Heritage Site.

The world's most remote airport.