Tangerine Dream - The Night in Romania 

This is another track from the soundtrack to Michael Mann's "The Keep", composed, arranged, and performed by the members of Tangerine Dream.
This track is one of the four pieces included on the album that are actually used in the film itself (the other three being "Puer Natus Est Nobis", "Heritage Survival", and "Canzone.") It is played during the scene where Prof. Cuza realizes that Molasar has deceived him and rejects his offer.
The video itself consists of some photos taken of the "Cave of the Crystals" in Naica, Mexico, plus a poster for the film and the cover of the novel. In case you're wondering why the images move by so quickly despite this being a rather slow piece, it's because I grossly overestimated how much material I could fit into the time span but did not want to waste any of this material. I know that might possibly kill the ambience, but I hope you'll forgive me.