The places here may look like movie sets, but they're real - and they prove earth is still a pretty mysterious place.

1. Singing dunes.

This sound is possible anywhere, made as sand vibrates against sand. I have to wonder who heard this deeply unsettling noise first, and how confused they probably were.

2. Salar de Uyuni, Bolivia.

The world's largest salt flat.

3. Waitomo Glowworm Caves, New Zealand.

A beautiful cave lit by - you guessed it - glow worms.

4. The Door to Hell, Uzbekistan.

Burning continuously for over 40 years, this natural gas crater has a name worthy of a death metal band.

5. The Hyperion Tree.

The world's tallest tree, Hyperion beats the Statue of Liberty by almost 100 feet.

6. Lake Hillier, Australia.

Oddly enough, nobody knows why it's pink.

7. Yellowstone National Park.

Mountain ranges, waterfalls and geysers perch on top of the world's largest supervolcano.

8. Pamukkale Hot Springs, Turkey.

These terraces are a World Heritage site, drawing visitors worldwide to wade and explore.

9. Angel Falls, Venezuela.

At over 3,000 feet tall, it's the world's highest uninterrupted waterfall.

10. Mendenhall Ice Caves, Alaska.

Hidden at the heart of the Mendenhall Glacier, these caves are a fading wonder; they exist only because Mendenhall is slowly melting.

11. The Sea of Stars, Vaadhoo Island.

Tiny, glowing plankton light up the night.

12.Mount Roraima, Brazil/Guyana/Venezuela.

A surreal plateau, Roraima exists at the intersection of three countries - and served as the inspiration for Paradise Falls in "Up."