Brains, Bones, and Ponce de Leon: The Strange Story of Florida’s Only Natural Hot Spring

It’s worth noting when Florida is in the news for contributions to human knowledge and not — to draw an example at random — one of its citizens throwing an alligator through a Wendy’s drive-through window.

In that vein, let’s turn our attention to the small Florida town of North Port, where a sinkhole formed 20,000 years ago continues to offer up clues to North America’s deeply buried prehistoric past.

Warm Mineral Springs, as the site is known, is an oddity even by Florida’s generous standards. Local legend holds that Ponce de Leon identified the spring as his sought-after Fountain of Youth. Before the conquistadors arrived, Native Americans held the site in high regard.

Hundreds of years later, a group of vacationing Ukrainian tourists, wooed by the mineral-rich waters, put down roots and invited family over to stay. Now North Port has five Ukrainian churches and a slew of Ukrainian restaurants to serve its 10 percent Eastern European population.

Soakers enjoy the mineral-rich waters of Warm Mineral Spring

Soakers enjoy the mineral-rich waters of Warm Mineral Springs. Photo: Shutterstock


Between the Spanish explorers and Ukrainian soakers, retired WWII Air Force Lieutenant Colonel and diving enthusiast William R. Royal discovered a human skull with a strange soapy substance clinging to it. He immediately assumed it was ancient brain matter preserved, somehow, by the spring’s mysterious waters.

Cold water

Royal, who’d later spend his twilight years searching for Atlantis off the Florida coast, also found a human thigh bone and the remains of ice-age animals like giant sloths, saber-toothed tigers, and camels. Based on a timeline of when sea levels would have been low enough for the sinkhole to be above water, Royal speculated that the human remains were at least 6,000 years old.

This was 1959, and the scientific community “poured cold water over his bold claims,” Barbara Purdy, author of The Art and Archaeology of Florida’s Wetlands, shared with Smithsonian Magazine. But eventual testing of the skull and strange substance revealed a surprise: Royal was right.

The skull was 7,000 years old, and the mysterious substance was indeed brain matter, preserved by anaerobic conditions at the bottom of the 76-meter-deep sinkhole.

Further excavation of the site in the 1970s uncovered a complete human skeleton, a find that turned out to be “dated to more than 11,900…years ago, making it the oldest human remains in the Western Hemisphere,” Purdy told Smithsonian Magazine.

Also found in the sinkhole: glass bottles from the 1930s, an entire Model-T automobile, and a 78-rpm phonograph record.

What’s next for Warm Mineral Springs?

Seventy percent of Warm Mineral Springs has yet to be explored. The unexcavated areas likely include human artifacts and more late-Pleistocene megafauna remains. The Springs are on the U.S. National Register of Historic Places, but that isn’t stopping the city of North Port from considering further development at the site.

A proposal for a 300-room resort has raised hackles in the Sunshine State. While many North Port residents take umbrage at the thought of tourists flocking to their haven like manatees to seagrass, scientists hope that whatever happens, the potential for research remains undisturbed.

“The city has been [a] good steward of the underwater archaeology by restricting diver access,” said Sarasota County Archaeologist Steve Koski in an interview. “Warm Mineral Springs should not be open for commercial tour dives or access without sound professional academic research…There is still great potential for research. There are likely more undisturbed human remains…and evidence of activities of the people who visited the site.”

Andrew Marshall

Andrew Marshall is an award-winning painter, photographer, and freelance writer. Andrew’s essays, illustrations, photographs, and poems can be found scattered across the web and in a variety of extremely low-paying literary journals.
You can find more of his work at, @andrewmarshallimages on Instagram and Facebook, and @pawn_andrew on Twitter (for as long as that lasts).