Across our planet, there are a handful of places that truly astonish, like Mount Everest, the Grand Canyon and Victoria Falls. These wonders seem to have little in common other than - literally - taking your breath away. But they share one other thing: they pose extraordinary challenges for their inhabitants. The first of two programmes in which cameras explore some of the most inhospitable places on the planet and the people who live there, including a team of Sherpa roping a route on Mount Everest's notorious Khumbu Icefall and, on the slopes of Mount Kilimanjaro, farmers fight pitched battles to save their crops from marauding elephants. In the Amazon rainforest, two boys undergo a rite of passage involving hundreds of ants with the most painful stings on Earth, and conservationists in the Grand Canyon try to ensure the survival of one of America's few surviving condor chicks.