What are the most unique natural wonders in the world?

There are many natural wonders in the world, but here are some of the most unique: 
 
  Grand Canyon, USA: Carved by the Colorado River, the massive gorge stretches over 277 miles and is more than a mile deep. 

 


  Northern Lights, Norway, Finland, Sweden, Iceland, Canada, Russia and Alaska: This natural phenomenon, also known as the Aurora Borealis,  occurs when charged particles from the sun collide with gases in the Earth's atmosphere, creating a colorful light show in the sky 

  Great Barrier Reef, Australia: This coral reef is the  largest living structure in the world and is home to thousands of  marine species. 

  Victoria Falls, Zambia/Zimbabwe: Located on the Zambia-Zimbabwe border, Victoria Falls is one of the  largest waterfalls in the world and is known for its impressive size and roaring sound. 

  Moeraki Boulders, New Zealand: Giant spherical boulders  found on a  New Zealand beach are believed to have formed over 60 million years ago.  Salar de Uyuni, Bolivia: This Bolivian salt flat  is the largest in the world and creates a mesmerizing, reflective surface after rain. 

 
 
  Chocolate Hills, Philippines: These unusual geological formations in the Philippines consist of more than 1,000 perfectly formed hills, named for their brown color during the dry season. 
 
  Door to Hell, Turkmenistan: This fiery crater in Turkmenistan was formed when a natural gas field collapsed and caught fire in 1971 and has been burning ever since. 

  Zhangjiajie National Forest Park, China: This Chinese park  is known for its towering vertical sandstone pillars  that inspired the scenery of the movie Avatar.  

 These are just a few examples of the many unique natural wonders  found around the world.