The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

An exquisite tunnel of cascading flowers.

Rippling sand dunes frozen in the Arizona rock.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

A terrific purveyor of natural history objects and curios.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

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

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

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A 140-year-old castle with underground caves hidden in San Francisco.

High on a hill overlooking Los Angeles lives a world famous, high power conical Tesla Coil.

A one-of-a-kind collection of a unique medium.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

A psychedelic labyrinth on the San Francisco bay.

A huge musical instrument played by the ocean.

The Dalai Lama named this New Zealand landscape the "Spiritual Center of the Universe."

Dolphins, ancient clams and hundreds of waterfalls make this one of the world's top tourist destinations.

Tubing through a cave lit with glowworms is a magical underground experience.

This Japanese-inspired labyrinth of hot springs is hidden in a Chilean forest.

The largest stone moai on Rapa Nui.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.