It's hard to believe a place like this still exists on the planet.
The Kimberley, in northwestern Australia, is like the Amazon you've never heard of. It's a massive stretch of pristine wilderness the size of California, largely untouched since the Earth was formed.
It has rainforests, towering desert rock formations and miles of unspoiled Indian Ocean beaches.
It has crocodiles, whales who come here to spawn, dugongs (sometimes called "cows of the sea"), and thousands of other plant and animal species. Many of them are rare and endangered.
The Kimberley is also home to aborigines who may make up the oldest continuous civilization on Earth, dating back some 16,000 years.
A recent "Nightline" visit to the Kimberley began with a chopper ride to pick up an aboriginal man named Alfie Oombaguy. He took us to an isolated beach where, in preparation for what we were about to see, he had us paint ourselves with rock dust. Then we bathed in smoke.
Oombaguy explained that we needed to have the country on our skin and to feel it.
"You know, like you know mother," Oombaguy said. "Here our country, mother. ... We respect it. And people all around, they can hear us."
Oombaguy called out in his native tongue.
"I'm saying 'I come to country,'" he said. "You know, the ocean, water. I come back, return to you."
The aboriginal people here have seen themselves as both guardians and in a way the children of this fragile ecosystem for millennia.
After the ceremony, we headed to a remote island to see one of the hundreds of ancient, secret and sacred aboriginal burial caves that line the coast.
As we hiked down rocks, Oombaguy talked to spirits all the way.
And then we found the bones.
These people, Oombaguy's, were thought to have been seven feet tall. They were tall enough to paint art on the roof of the cave, featuring images of "wanjinas," or spirits.
Oombaguy said the paintings were a form of prayer. The aborigines would paint a rain spirit, for example, as a way to pray for rain.
This place is now, many believe, under threat -- and could someday be threatened by the type of pollution we're seeing in the Gulf of Mexico right now.
An international consortium of huge oil companies, including Chevron, the American oil titan, wants to ramp up drilling for natural gas off the coast and to build a massive natural gas plant here.
"We remain committed to the responsible and economic development," Chevron told us in a statement.
But critics say this project would be the first step toward industrializing one of the last untouched parts of the planet.
"It'll devastate the area," said Robert Vaughn of the group Save the Kimberley. "It'll be like living in Beijing."
Peter Tucker, Vaughn's colleague, agreed. "There's nothing like it on this Earth, and it would be an absolute tragedy to see the Kimberley become an industrial precinct."
"There is nothing like this in the world. And we can't believe that the Australian government is preparing to do this. It's out of sight, out of mind. It's this chunk of country on top of Australia which hardly anyone visits and yet it is unique. It takes your soul away and holds it there and never lets it go, and we think it's worth fighting for.