Known as Gafsa Beach, or Lac de Gafsa, it quickly inspired its own Facebook page even though authorities have warned that its water could be contaminated with radioactivity or other hazards.
“Some say that it is a miracle, while others are calling it a curse,” journalist Lakhdar Souid told the TV channel France24.
He wrote in the Tunisia Daily that the lake "is located in an area rich in phosphate deposits, which leave residue that is sometimes strongly radioactive."
Geologists say the lake could have been formed by seismic activity or a disruption in the water table that caused groundwater to rise to the surface.
Despite the warnings, Lac de Gafsa has tall cliffs that locals say are perfect to dive from into the deep water.
But one discouraging development is that the color of the lake has changed from a clear turquoise to a murky green due to algae growth since it was first discovered.