"[Helictites] are only found in 5 percent of caves throughout the whole world. And we have the largest display in Black Chasm in the U.S.," Busbee explains.

Discovered by miners in 1854, the cave is now family-owned and open every day for 45-minute tours. Hardcore cave enthusiasts come from all over the world to check out this natural wonder that’s just an hour east of Sacramento.

After explaining a few rules -- like don't touch or lean against anything -- Busbee unlocks the iron gate at the mouth of the cave and leads me down a steep, narrow set of wooden stairs.

Immediately, I feel like I'm descending into an entirely foreign world.

"It sort of feels like I'm in Disneyland," I remark, to which Busbee responds, "Yes! It reminds me of that movie, 'The Goonies'."

The cave is dimly lit, but Heather uses a flashlight to show me the glittering walls of blue marble and brown limestone. As we stand on a wooden platform, she points out crystals as big as cars and helictites as tiny as sewing needles.

It is totally breathtaking.

And then, just when I don’t think it can’t get any cooler, Busbee leans over the railing and points out the lake.

YES. A LAKE AT THE BOTTOM OF A CAVE. I peer over the edge of the railing and spot it, 80 feet down. At first glance it looks like a neon blue puddle. It is so gorgeous and tempting that I have to ask if people are allowed to swim in it.

She says there is a little blow up raft down there that staff take across the water sometimes.

"It's really fun!" she says. And she adds, "You can drink that water, all it is is mineral water, really."

We follow the path down more wooden steps and end up in a huge room called the Landmark Chamber. It’s known for its breathtaking ceiling, which is covered with different crystal formations. It’s also famous for inspiring a scene in 'The Matrix Reloaded.'

While the production crew wasn’t actually allowed to film down here, Busbee tells me that they have held weddings and concerts in the Landmark Chamber. The acoustics down here are insanely good, but I can’t imagine any of my claustrophobic family members being OK with me getting married 100 feet underground.

As we start the walk back up to the mouth of the cave, the only thing we can hear is the echo of our footsteps. No cars, no birds chirping, nothing. We’re totally alone ...

Wait, never mind.

Heather spots a salamander -- called an ensatina -- no bigger than a matchstick, perched on a limestone rock.

But this little guy is not a fan of our flashlight, so he scampers back into the darkness.

When we finally emerge above ground, the sun feels warm on my skin. The trees, birds, and clouds -- they seem so foreign from the world we just spent an hour in.

Black Chasm Cavern is one of the most unique places I’ve ever been to in California, and a good reminder that you never know what beauty lies right underneath your feet.