Formed millions of years ago during the ice ages, these rare images show cenotes at the Rivera Maya in Mexico.
Photographer and diver Martin Broen, from New York, captured these incredible scenes when diving in more than 60 different caves located between Playa del Carmen and Tulum.
Describing it like floating through a different planet, the natural swimming holes were formed by the collapse of porous limestone bedrock, leaving a secret world of groundwater pools.
The “sacred wells” were celebrated by the Mayans, but were also used as a place for human sacrifice by some.
Martin decided to explore the cenotes to try and capture their hidden beauty, which is often dismissed by divers as a lifeless place.
“For many years I [have] been trying to capture the beauty and differences of the Cenotes and underwater cave systems,” the 50-year-old from New York said. “They can offer divers a unique set of surreal experiences which are closer to space exploration or traveling back in time.”
He added: “The caves took millions of years to form during the ice ages when the caves were dry, and then got preserved in time when the sea level rose and the caves got flooded, preserving incredible formations as well as fossils of the first humans of the region and megafauna which are extinct.
“The water in the caves gets filtered through the rocks and therefore is crystal clear, so gives a complete feeling of flying inside those alien-like spaces, closer to be exploring a different planet.”
The product designer and innovation manager said the science and history behind the untouched caves is what makes them so fascinating.
He added: “The light of the sun at the entrance or the one from your lights deep inside the cave may get modified by tannic acid that accumulates from the rainfall producing strange green and red like tones, or seeing super defined haloclines dividing the layers of fresh and salty waters, creating visual effects which are not common on the surface and make you feel inside a science fiction movie.
“There are truly unique and magical environments which are just below our feet, which are little known and not as appreciated.”
Martin describes the problems that come with trying to photograph such a difficult underground environment.
He said: “There is no light besides the one you bring with you, so you are pushing the sensor and optical limits of your camera at every shoot, shooting at very low speed while holding your breath, while maintaining your buoyancy and being sure you don’t damage any formation, and you are doing that while in control of your redundant scuba gear as you may be minutes or even hours away from the closest exits to surface.”
Epoch Times staff contributed to this report.