The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Northern Ireland's Brobdingnagian stepping stones.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Each year, one talented artist puts on a show sculpting twelve butter-based busts of dairy princesses.

The first patented shaved-ice machine heralded a snowy wonderland of iced treats at a favorite New Orleans summer shack.

This failed condo development was reborn as a street art hub.

The world's tallest statue of an American hero.

The petroleum industry brings you the joys of hydrocarbons and largest collection of antique oil rigs in the world.

The highest point in Texas is capped by a big silver pyramid.

A collection of massive stacked rocks in Texas includes a snarky note on the benefits of modern technology.

A museum marks and documents the site of the Titanic's launch.

A historic freight system that found the true gold rush is in tourism.

A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

The most powerful waterfall in all of Europe.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

This volcanic cave lake is essentially hard proof that Iceland is the most magical place on Earth.

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

A formerly glacier-tipped volcano that inspired none other than Jules Verne.

A sulfuric martian landscape that looks far better than it smells.

Three columns of volcanic rock shoot out of the ocean.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

Iceland's largest lagoon is home to stunning multi-colored icebergs.