Gorgeous photos, detailed maps, and a moving personal narrative narrate grueling expeditions to the source of Africa's famous Okavango Delta, a sanctuary of biodiversity.

Explorers discover signs of Angola's ghost elephants-presumed extinct after decades of civil war but now reappearing in the highlands wilderness.

Follow intrepid explorer Steve Boyes as he leads the National Geographic Okavango Wilderness Project, documenting the little-known lakes and rivers flowing through central Africa to the vast Okavango, a region supporting the world's largest elephant population as well as lions, cheetahs, and hundreds of bird species.

For miles on end of twisting waterways and leech-filled swamps, Boyes and his fellow explorers pole their flatboats with only satellite imagery and hippo trails to guide them. Sometimes they must drag their boats through dense bush or mud-thick waters. An angry hippo threatens to overturn the caravan; swarms of bees dive-bomb explorers' ears and eyelashes. In Angola, closed off by war for decades, the team tracks ghost elephants-a subspecies thought to have disappeared forever.

By day they press on, by night they camp under the stars. Lions roar and hyenas howl in the distance. Locals become friends and fellow travelers-guardians of the rivers, sharing generational knowledge of these waters they call the "source of life."

With more than 100 photographs and maps, including a foreword by Prince Harry and portraits of local wisdom keepers, this beautiful book provides a glimpse of primeval wilderness still thriving on the planet-and the grit of explorers determined to preserve it.