Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

An average of 33 million gallons of water pour out of the collapsed cave at the heart of this spherical spring.

With over 12,000 different species of plants, this botanical garden is Japan's oldest and most diverse.

An underground city of salt.

Will Geer's outdoor theater started as a mountain retreat for actors, musicians, and other artists who were blacklisted during the Red Scare.

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

This legendary urban waterfall creates a dazzling display of rainbows.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

An encyclopedic collection of mammal penises.

A relatively obscure antihero from the Marvel Comics universe adorns a wall inside Iceland's main airport.

Walk in the footsteps of the gods and straddle two tectonic plates.

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

Iceland's "Smoky Valley" is a beautiful river that is shrouded in a constant cover of steam clouds.

This black shoreline is made up of exploded lava particles.

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.

Three columns of volcanic rock shoot out of the ocean.

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

This replica Viking village was created for a film that was never shot and is now open to visitors.

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

One of the last remaining movie theatres in the country that features a rear-projection system.

Impossibly life-like natural history models created out of glass by a father and son.

A beacon atop a downtown building provides Bostonians with weather forecasts and baseball news.