If you're looking to save endangered species and protect the world's wildest place, it's not a bad idea to go and see them. "Without tourism most of the remaining wild areas of the world would cease to exist," says Ian Salisbury, general manager of The Bushcamp Company in Zambia. "If we are to conserve habitats and abundant wildlife, then these areas have to be able to generate income, so that governments and other agencies can pay for their upkeep. In effect, the animals have to pay for their own survival, and if people are prepared to pay to spend time watching or photographing them in a sensitive and responsible way, then that is surely better than allowing their decline through loss of habitat or hunting." The dollars that come from responsible, sustainable tourism like safaris and expeditions to the remote corners of the world have hugely positive effects upon preserving the wilderness. With that in mind, here are 10 once-in-a-lifetime trips that you can take that also help.