(CNN) The way Jason Momoa describes Hawaii's beloved dormant volcano, Mauna Kea, makes you understand why it's considered sacred.

"It's kind of the umbilical cord to earth," the actor tells CNN. "You know, if you think about the Hawaiian islands, that's the biggest mountain in the world, right? All the way up. So Mauna Kea is the most sacred. They call it the belly button, too. That's like our birth place. You can imagine that in the middle of the ocean. That's how our islands were formed. So how can that not be sacred?"

He would know. Momoa, a native of Hawaii, has had a near-constant presence there when he's not working, fighting with local protestors to stop the construction of the Thirty Meter Telescope, or TMT, which would drill directly into the mountain and, according to critics of the project, invade its precious water supply. (Between the foot of Mauna Kea and the summit measures 10,000 meters, making it the "tallest" mountain in the world.)

So far, protestors have successfully blocked the only road crews seeking to ascend the mountain in order to build the billion-dollar observatory can use.

"It started in 2015, heard the news about it and you know, it's, it's my home. I'm Hawaiian. It's my nationality. What's happening over there was just not right," Momoa says. "And I wanted to bring awareness to it. And I went over there to meet with everyone and from then on, it's just been this constant as a devotion to bringing awareness to the world."