Gentle giants of the deep. The largest fish in the world. Whale sharks. It doesn't matter what you call them, these massive animals are incredibly elusive. Predominantly solitary, the chances of just happening upon one is slim to none. That is unless you're in Djibouti (specifically the Gulf of Tadjoura) between October and February. It is here whale sharks congregate in one of the highest densities on Earth. While nothing in life is guaranteed, the chances of not only seeing one but multiple whale sharks is about as close to 100% as you'll get. To make things all the better, swimmers and divers load into little zodiacs in a paramilitary-esque operation hoping not only to see them, but to swim alongside them. Truly an amazing experience.