While most think an oasis in the desert is at best a mirage, this is not always so, as is the case of the jewel of the great African Kalahari Desert, Okavango. This nourishing delta, the largest within the borders of the Dark Continent, is the lifeblood for thousands of weary animals making the trek across the unforgiving sun-baked lands of Zimbabwe. Brought to video by National Geographic, this documentary... see more