CAVE OF FORGOTTEN DREAMS Werner Herzog: Germany’s grumpiest leprechaun.

THERE'S A SCENE in Werner Herzog's 3D documentary Cave of Forgotten Dreams when his guide through the Chauvet Caves instructs the touring party to stand still, be silent, and listen to the pure sound of life deep beneath the Earth. The silence is supposed to be so profound, a man can hear his own heartbeat. The moment ends up being profound for the viewer, as well. Check yourself. I bet you're holding your breath.

Cave of Forgotten Dreams is an amazing achievement. Until their discovery in 1994, the Chauvet Caves had been buried for tens of thousands of years, their contents preserved as an important historical record of a time long past. The oldest known prehistoric paintings cover the interior walls, and the environment is so delicate that visitors are banned from this massive underground cavern. Only a handful of scientists are allowed inside, and even they must stay on a walkway barely two feet wide.

Herzog being allowed to film inside these caves is a tremendous thing; that he has done so in three dimensions means the rest of us get a virtual tour of this wondrous setting. The photography is remarkably rendered: These rocky surfaces and sparkly crystalline sediments are so beautifully realized, you really might forget yourself and reach out to touch them. (I did, more than once.) Of course, Herzog is equally fascinated by those who study the caves: As in 2007's Encounters at the End of the World, he introduces us to the amazing people who explore the unknown. Tying it all together is the director's monotone narration, laying out in his kooky philosophy what all of this means for mankind. "Vhen ist ah preehiztorick cave like a Brookleeen phone boook?" Don't worry, Werner will tell you!

It's as hard to oversell how good Cave of Forgotten Dreams is as it is to describe its ethereal charms. No matter how many IMAX National Geographic films you've seen, you haven't seen anything like this—and you need to see it in a theater, connected to an audience, reaching back across human history en masse to get the full significance of what Herzog's bringing together. If Cave of Forgotten Dreams proves anything, it's that life is not hermetically sealed. We must always be looking and exploring if we're ever to understand who we are or where we came from.