Singing sand dunes
Filming in the terrible heat, dryness and clogging dust of shifting sand deserts adversely affects both crew and equipment. Uncooperative camels, and having to translate into Chinese and then to local dialects really slowed things down. But worst of all, the singing dunes just wouldn't perform while the crew was there. A trip to western China six months later proved fruitful though when a low, distant moaning during lunch gradually emerged as the longed-for sound.