A little-visited waterfall in an otherworldly landscape.

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

The most powerful waterfall in all of Europe.

This elegant arc of a waterfall marks a religious turning point.

An encyclopedic collection of mammal penises.

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

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

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

A medieval castle in the middle of rural Texas.

This small park features a monumental fountain wall, providing a great photo opportunity in the middle of Houston.

A tiny waterway named after a ghost story.

Modern technology and live displays tell the story of the Pacific during WWII for the Internet generation.

No one is sure why this mysterious tradition started.

This unique tower has been home to malaria-fighting bats for 100 years.

Take a leisurely ride on a 1906 cable car or a 1907 steam locomotive.

An unexpected connection to Chicago awaits visitors on an island just off the California coast.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

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

A cave's rare beauty held a cavernous secret hidden underground.

Once seen as a bit of an eyesore, this sculpture has become a staple of downtown Houston.

This seaworthy collection was sparked by one man's passion for sailing.

Ghost town with a beer-drinking goat for mayor.

An abandoned quicksilver mining town surrounded by the Big Bend parks.