That was awesome - the best thing I've seen in a long time - the little girl at 4:21 with the giant hat and feather was my favorite. And ditto the music - perfect.
I visited the Goreme open-air museum in Cappadocia, Turkey and they used this same principle. There were square, shallow holes dug into the cave's dirt/stone floors, and the guide said they filled pots with food and surrounded them with clay that they kept moist - an early regrigeration system. http://www.youtube.com/watch?v=tHRT2Tiyaek