Dr. Robert Ballard, the famous adventurer who discovered the Titanic, is profiled alongside other contemporary explorers in this National Geographic documentary. Deep-sea researcher Sylvia Earle, Egyptian archaeologist Dr. Zahi Hawass, star mountaineer Heidi Howkins, and a new generation of cartographers and dinosaur hunters all contemplate what it means to be a modern explorer, to push oneself beyond physical and mental boundaries and into the unknown. One spectacular sequence follows a group of men into the jungles of Tibet to find the "mythical" waterfall of Shangri-la.