Werner Her­zog is one of my favorite direc­tors (Wheel of Time, Encoun­ters at the End of the World). His films have a way of draw­ing you into another real­ity through stun­ning visu­als and long shots that allow your eyes to mar­i­nate in the beauty of what­ever sub­ject he is shoot­ing. Cave of For­got­ten Dreams is his lat­est cre­ation released in Sep­tem­ber of 2010 — and it’s in 3D.

The doc­u­men­tary, which hits the­aters this spring, focuses on the Chauvet-Pont-d’Arc Cave in France. The cave is tens of thou­sands of years old, and for many thou­sands of those years no human being knew about it. Three French explor­ers dis­cov­ered the cave in 1994.

So, what makes this cave wor­thy of a 3D doc­u­men­tary from one of the world’s great film­mak­ers? For one, the cave con­tains amaz­ing detailed draw­ings that defy explanation.

Giz­modo explains: “The walls con­tain hun­dreds of animals—like the typ­i­cal Pale­olithic horses and bisons—but some of them are not sup­posed to be there, like lions, pan­thers, rhi­nos, and hyenas.”

Appar­ently, some of the paint­ings are of crea­tures that don’t exist. For exam­ple, an ani­mal that looks like a half-woman, half-bison. Giz­modo spec­u­lates that these artis­tic lib­er­ties may have some­thing to do with the copi­ous amounts of car­bon diox­ide and other gases in the cave. The the­ory is that hal­lu­ci­na­tions in the cave were common.

To secure per­mis­sion to film in what is inar­guably a French national trea­sure, Her­zog had to agree to bring just a few crew mem­bers with him and make sure every­one wore spe­cial suits and shoes the entire time so as not to dis­turb the find. Also, due to the high lev­els of car­bon diox­ide, Her­zog and com­pany could stay in the cave for only a few hours at a time. Safety first.

The film was inspired by a 2008 New Yorker arti­cle by Judith Thur­man. Even though it’s a doc­u­men­tary about a cave few peo­ple could pro­nounce let alone find on a map, the Web searches are soar­ing. Online lookups for the movie have spiked over 400% dur­ing the past week. Clearly, movie­go­ers are excited to join Her­zog on his lat­est adven­ture. No spe­cial suit or shoes required.