Decoding the Secrets of an Ancient Maya Cave

Why you should care

Because climate change has been affecting civilizations for a long time.

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When archaeologist Holley Moyes first poked around Belize’s Actun Tunichil Muknal cave, the massive amount of bat feces impressed her. Sure, the ancient Maya pots and tools dazzled Moyes. But during early trips into Actun Tunichil Muknal, it was the piles of poop that alerted her to the uniqueness of this ancient site.

“There were seven or eight centimeters of almost pure bat guano and almost no charcoal, and I thought, ‘Hey, what is this all about?’” says the University of California, Merced, professor. Given that pine torches would’ve left a charcoal carpet, “it was a dead giveaway that bats were coming in, but people weren’t.”

Like many Maya sites, though, Actun Tunichil Muknal — Cave of the Crystal Sepulchre, known as ATM to researchers — generated as many mysteries as it solved. Why did the Maya seal the cave for centurylong breaks and then reopen it? Why did they journey deeper and deeper into the earth over time? What was the purpose of the human sacrifices that litter its chambers?

ATM is one of hundreds of limestone caves in the jungles of western Belize. For decades, scientists swarmed the grand cities dotting the area, but in 1959, a guide discovered a cave in Chichén Itza in southern Mexico filled with Maya artifacts, according to The Ancient Maya of Mexico, edited by Geoffrey E. Braswell. Quickly, Maya studies expanded to include subterranean sites. But few compare to ATM, which was mapped in the mid-’90s by a team that included Moyes.

The ancient Maya don’t write very much about caves. But they were using them like crazy.

Holley Moyes, archaeologist, University of California, Merced

Scientists discovered its most impressive treasure only after navigating an underground river and descending a quarter-mile below the surface. The reward: the Crystal Maiden, the skeleton of a 20-year-old covered in sparkling, naturally occurring calcite. The maiden, whom experts believe was offered by priests to Maya gods more than a millennium ago, is one of 14 human sacrifices hidden in the cave.

During the heyday of the Maya civilization, from roughly A.D. 250 to 950, hundreds of thousands of people lived in cities throughout Central America. The largest urban area, Caracol, in present-day Belize, had a population of 140,000, according to research by Diane and Arlen Chase, husband-and-wife anthropologists at the University of Nevada, Las Vegas. The cities devoted room to sacrificial burial grounds, so why did priests bother battling underground rivers and scramble up and down slopes covered in guano to offer up a sacrifice?


It’s especially baffling, given that the Maya underworld, Xibalba, is a nasty place. Lords of the nether realm sported such names as “One Death, Seven Death, Pus Master, Jaundice Master, Trash Master [and] Stab Master,” writes Andrea Stone in Images From the Underworld. They were “the ghouls and goblins of the Maya Pantheon.” Sadly for the Maya, occasional trips to “the place of fear” were a necessity.

They might have had to make the journey as a rite of passage or as part of a kingly ascension ceremony, says Moyes. The rituals in caves are considered highly esoteric, and for a long time there wasn’t much about them in ethnography, she notes. When ethnographers first started working in Maya areas, they weren’t invited to the cave ceremonies, Moyes says. “You didn’t take foreigners there.”

“The ancient Maya don’t write very much about caves,” says Moyes. “But they were using them like crazy, especially in the late classic period, there is this whole boom in cave use.”


A human skull inside Actun Tunichil Muknal, the Cave of the Crystal Sepulchre.

Source Alamy

Through carbon-dating, researchers discovered that the remains near the entrance of the cave are older than those tucked deep into the darkness. Over hundreds of years, the Maya journeyed farther and farther into the cave system — many experts think drought near the downfall of the Maya empire in the middle of the 10th century created a desperation that forced the people to bring sacrifices closer to the home of certain gods.

“It has to do with climate and stress, part of a nexus of how the environment and human rituals all come together,” Moyes says. “They must have been pretty panicked, because ritual life increases dramatically in this period.”

Scientists are still stumped by much of Maya history. Maybe a layperson will stumble on a key to one of the mysteries. For years, ATM remained closed to the public, but reaching the portal to Xibalba these days requires only an hour’s drive from San Ignacio, followed by an hour of hiking through dense jungle, fording streams and swimming across the pool at the cave’s mouth. After that, an amateur Indiana Jones has only to wade a kilometer along a subterranean river, where the Crystal Maiden awaits.

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