Atrium Carceri - Observatory

What you hear:
("Atrium Carceri" - "Observatory" from the album "Ptahil")
The fourth album from composer Simon Heath (Sweden) ventures beyond the vestiges of your mortality, granting a fleeting glance at the world beyond the veil. As ever, Simon has reinvented the genre as well as himself with a unique ambience created from his ever-increasingly complex and obscure techniques of mental dissolution and musical innovation. (Cold Meat Industry)

Ambient music is a musical genre in which sound is more important than notes. It is generally identifiable as being broadly atmospheric and environmental in nature. It's primary feature is that the music is intended to drift in and out of the listener's awareness while creating its effect on the listener's consciousness.
Dark ambient is a general term for any kind of ambient music with a "dark" or dissonant feel, but often involves extensive use of digital reverb to create vast sonic spaces for frightening, bottom-heavy sounds such as deep drones, gloomy male chorus, echoing thunder, and distant artillery. It has an eerie feel. Generally the music tends to evoke a feeling of solitude, melancholy, confinement, and isolation. However, while the theme in the music tends to be "dark" in nature, some artists create more organic soundscapes. (Wikipedia)

What you see:
This is a flash animation called "Infinite OZ" made for one of the mini series of SciFi channel: "Tin Man". It is a re-imagining of L. Frank Baum's classic "The Wizard of Oz". You can watch the flash animation here:
http://www.scifi.com/tinman/oz