If you visit Tanzania, you must visit Ngorongoro Crater, a conservation area that is home to the "big 5" (the elephant, lion, leopard, buffalo and rhino). I have been there three times and each time is unlike the other. Ngorongoro is the largest unbroken caldera in the world - a deep volcanic crater. The number of safari vehicles are limited each day to a certain number so it doesn't become overcrowded. My fondest memory was my last visit when it started to rain as we were heading to our exit. Before climbing the steep dirt road we stopped, turned off the engine of our Land Rover, and sat quietly as the rain fell. Tranquility.