Elon Musk's grandparents were adventuring pilots who spent years looking for a lost city in the desert

It's no wonder Elon Musk, the CEO of SpaceX and Tesla, is the most interesting man in tech - he's got adventure in his blood.

Musk's maternal grandparents were Dr. Joshua and Wyn Haldeman, celebrities in their time for their expeditions to find the Lost City of the Kalahari, which legends held was located somewhere in southern Africa's Kalahari Desert.

In 1948, at age 45, Dr. Haldeman, a chiropractor in Sasketchewan, Canada and a leader in local politics, got his pilot's license. With his small, single-engine airplane, he could spend more time at his practice and less time traveling by train, according to an article by the Canadian Chiropractic Association.

By that point, he and his wife Wyn, a dance instructor, had three daughters: Lynne, and twin daughters Maye (future mother of Elon) and Kaye. The plane became a family hobby, as they jetted around North America so Dr. Haldeman could attend chiropractic conferences.

Then, in 1950, The Haldemans moved from Canada to South Africa, with only six months notice, despite never having so much as visited the country. 

Historical sources are torn on whether Dr. Haldeman, a chiropractor by trade, wanted the move because he saw a moral decline in Canada. Other reports indicate that he was getting restless and wanted adventure. Either way, they crated up Dr. Haldeman's tiny plane and brought it with them on their 30-day boat trip to South Africa.

After the move to South Africa, the Haldemans became minor celebrities for their aerial exploits: One 1954 trip, up the coast of Africa and across part of Asia to get to Australia, was a 30,000-mile trek, says the Canadian Chiropractic Association.

A dead civilization

But the Haldemans' real passion was searching for the Lost City of the Kalahari, which explorers had been looking for since 1885, when Canadian explorer Guillermo Farini claimed to have found ruins of a dead civilization in the desert.

Starting in 1953, the Haldeman family, often including the children, went on 12 expeditions to find the Lost City. The second expedition, at least, was an 8,200-mile trek flying 200 feet over the desert sands. When son Ankor Lee Haldeman was born in 1955, he joined along too.

 Though they never found any evidence for the Lost City in about a decade of regular expeditions, the searches alone made the Haldemans famous in certain circles, and they curated slideshows and maps of their adventures that they would show to friends and strangers alike.

"My parents were very famous, but they were never snobs," Maye Musk told the New York Times earlier in 2016.

Dr. Haldeman passed away in an air crash in 1974, and is said to have believed in the Lost City of the Kalahari for all of his life. Maye Musk, Elon's mother, went on to an accomplished 50-year career in modeling and entrepreneurship.

As a coda to the story, a 2016 episode of the Travel Channel's Expedition Unknown claimed to have found buildings in the Kalahari that could potentially match the legend, possibly presenting a solution to the mystery that vexed the Haldemans.