It takes a unique set of circumstances to build something the size of the Great Barrier Reef, the most important of which is its perfect location. 

 

This entire reef sits in the tropics. And that means warm water and strong sunlight all year round. Without them, it simply could not grow to this colossal size. So how did the Great Barrier Reef end up here perfectly located? Has it always been here? The geological evidence says no. 

 

Incredibly, it seems Australia started life about as far south as you can get, as part of Antarctica, far too cold and far too dark for this epic reef. But the evidence of this incredible transformation isn't in the sea. It's found inland. Something so big, it transformed this place from a cold, dark world to a warm, tropical paradise.

 

The answer is locked up in a series of mountains that stretch up Australia's eastern coast, like rocky backbone, called the Great Dividing Range. Geological super sleuth Kurt Knesel is on the hunt for the right mountain, one that holds the answers. But this mountain range is 2000 miles long, so he’s working with a paraglider Will Gadd to cover more ground. Kurt is looking for this spectacular peak. It is called Mount Warning, and it has a violent past.