Giant origami sculptures tucked into desert scenery beckon passers-by to explore further.

This famous Nevada gold mine, once a hotbed of Wild West shenanigans, is now open for tours.

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

Twisted girders are all that remain of an Icelandic bridge that was wiped out by a combination of volcanic heat and glacial floods.

The most powerful waterfall in all of Europe.

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

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

Rising from the sea like a stone monster.

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

Double spiral staircases are not unheard of, but they are very rare.

A huge musical instrument played by the ocean.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

A massive underwater sinkhole made famous by Jacques Cousteau.

A bizarre house filled with an astounding array of collections.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

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

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.