Crawl into the Maya underworld, where science meets spirits, shamans, and snakes. A long-forgotten cave could shed light on one of history’s most enduring questions: why did the ancient Maya collapse?
PETER GWIN (HOST): Back in the 1960s, a teenager in Mexico noticed something strange. He was helping his dad with some farm work.
GUILLERMO DE ANDA (ARCHAEOLOGIST): And he realized how dry is all the land right now because there has not been rain. But he spotted a tree in the middle of this dryness and this tree had flowers. And he said how come this tree could be so green and have flowers.
GWIN: Guillermo de Anda is an archaeologist on Mexico’s Yucatan peninsula. And what this teenager found decades ago would change Guillermo’s career.
DE ANDA: So he approaches there. He saw this little depression on the ground. He said, there must be water down there. And he started excavating.
GWIN: And as the teenager dug deeper, he started noticing bursts of cool air. It felt like air conditioning. And he thought, maybe it’s a sign of water.
DE ANDA: To his surprise the water was not nearby but there was this amazing cave.
GWIN: An amazing cave that the Maya had sealed up long, long ago.
DE ANDA: This is something that the Maya used to do. They do termination rituals in caves. It's like we're not using this cave anymore. We are not going in there. So let's close it forever.
GWIN: Now it was open again. But not for long...
DE ANDA: There was an archaeologist. He get to the site, and two months later he decided to reseal the cave. And he said this time it's going to be sealed forever.
GWIN: Why’d that archaeologist choose to reseal the cave? That’s a mystery. But it’s not where the story ends. Because fifty years later, Guillermo and his team reopened the cave. And this time, they’re not sealing it back up. Welcome to the Cave of the Jaguar God.
I’m Peter Gwin, and this is Overheard at National Geographic, a show where we eavesdrop on the wild conversations we have here at Nat Geo, and follow them to the edges of our big, weird, beautiful world. This week, Guillermo takes us into the Maya underworld in search of an answer to one of the history’s most enduring mysteries: Why did this great civilization collapse? We’ll have more after the break.
GWIN: We should probably just get this out of the way. No one actually calls Guillermo de Anda “Guillermo.”
DE ANDA: Most people know me as Memo. It’s much easier than "Guillermo".
GWIN: For more than 30 years, Memo has been crawling, climbing and squeezing his way through caves in Mexico’s Yucatan Peninsula. He’s a researcher with Mexico’s National Institute of Anthropology and History.
DE ANDA: I describe my job as the best job in the world. So this is because I have a chance to do science, to do research, to do exploration, extreme sports, and have fun at the same time.
GWIN: But Memo almost didn’t become an archaeologist. He took a break from college and became a diving instructor in Cancun. It wasn’t the coral reefs that captured his imagination. He became interested in the sinkholes unique to the Yucatan Peninsula. They’re called cenotes.
DE ANDA: A cenote is basically a flooded cave. It's typically a cave where the ceiling have collapsed. So they are beautiful because they are windows to the great Maya aquifer that lays beneath our feet in all the Yucatan peninsula. Sometimes you're walking in the jungle. You see one of these big holes and they are sinkholes, basically. You look at the water, you see this crystal clear blue water. The sun shining there. So it's an amazing, magical experience.
GWIN: Magical… but they aren’t always this easy to find. Some are big tourist attractions,
with a parking lot filled with tour buses. Others have been hidden for centuries, their entrances only a tiny opening hidden by a pile of rocks. And then there’s the safety issue. Okay picture this—once you get inside it’s like being in an underground labyrinth: dark, flooded passages leading in all directions, totally easy to get lost and never be found. And there’s no telling what’s in the water, either. That’s one reason why when Memo first got to Cancun in the 1980s, diving into cenotes wasn’t that popular.
DE ANDA: Nobody wanted to go in the water in the cenotes. I mean they said it was not worth it. It was dangerous. But I was so attracted to them.
GWIN: And it was this attraction that got Memo back onto the path of becoming an archeologist, and eventually a Nat Geo explorer. Because he wasn’t just finding beautiful rock formations in the cenotes. He was finding evidence of the people who had been there before him.
DE ANDA: In one of these dives I saw a human skull. And that human skull changed my life. So I am dedicated completely now to diving in these places to do science.
KRISTIN ROMEY (WRITER, NATIONAL GEOGRAPHIC): You got a lot of cave divers, you got a lot of archaeologists. But very few where that Venn Diagram intersects with cave diving archaeologists. He is Mr. Cenote.
GWIN: Kristin Romey’s a colleague of mine at Nat Geo. She covers archaeology, and she’s actually been diving with Memo. She told me that in those cenotes, she’s also seen human bones.
ROMEY: We know that the Maya sacrificed people and objects by tossing them into a cenote. And so sometimes you'll be lowered down the hole into the water and you're just bobbing on the surface and the water is crystal clear in the cenotes. I'll just drop my flashlight, point it down, and 150 feet below me is a perfectly articulated skeleton next to like a piece of pottery sitting upright.
GWIN: Skeletons from human sacrifices in underground, flooded caves. Sounds pretty gruesome. But archaeologists like Memo say these caves could hold clues to a whole new understanding of the ancient Maya in the Yucatan. Like most stories written long after the fact, the story of the ancient Maya is a complex collage that historians and archaeologists
have been piecing together over time, starting with Maya ruins.
ROMEY: Well if you look at Chichén Itzá you have, you know, the amazing pyramid that everybody knows.
GWIN: Okay to be honest, I had heard of Chichén Itzá, but I didn’t really know what it was until I went there recently. So first of all, there’s tons of tourists. And you see this huge complex—all these stone buildings, like downtown of the ancient city. But there’s one clear centerpiece. This stair-stepped stone pyramid that just dominates everything around it. And when I first saw it, I wondered, how the heck did the ancient Maya build this in the middle of the jungle?
But building this impressive structure—it was just one of many accomplishments. Besides the grand architecture and beautiful carvings, the ancient Maya mastered astronomy and an advanced system of farming that at one point fed millions of people. The Maya were one of the great civilizations, like the Babylonians, the Egyptians and the Romans. You know, the type of civilization that doesn’t just fall off the map. Except, about a thousand years ago, the ancient Maya did just that.
ROMEY: Ultimately I think the biggest question about the Maya is that there was always this idea of a collapse because right around 850 A.D. to 950 A.D., all of a sudden these great thriving cities just... there's no more building, there's no more activity. And we're trying to figure out what happened there.
GWIN: So Memo is looking for answers in Chichén Itzá. Today, it’s full of tour groups and souvenir vendors and people snapping photos. So what could be left to find? Well, the ancient city was much bigger than the pyramid and the surrounding structures. And Memo thinks there’s more to learn in the rest of the city. Especially underground.
ROMEY: We know that there are certain very important cenotes right around Chichén Itzá. Memo is exploring the pyramid, and he's also looking for other cenotes and trying to understand how the Maya world aboveground and the Maya world below ground are integrated in Chichén.
GWIN: Memo wants to find out how Chichén Itzá became powerful, and why it didn’t stay that way. What were people’s lives like there? And what role did the underworld play?
DE ANDA: There's not only caves, there is artificial tunnels. There is cenotes, there is rock shelters. All this is going to give us a very new perspective about Chichén Itzá. And we will learn, I'm sure, that the underground features were way more important than we thought.
GWIN: So when Memo got a tip about a new cenote on the outskirts of Chichén Itzá, he jumped at the chance to check it out.
DE ANDA: It's one of the most visited archaeological sites in Mexico. There is a lot of tourists going there every year. You go there and it's a given day and the place is crowded. And only two thousand meters away from the main temple, there is this cave that was hiding for a long time.
GWIN: But when he got there, at first he didn’t find the cenote. Just a pile of stones. He and his team started uncovering them, just like the teenager did a half-century before. And that’s when they found it: the entrance to the sealed cave.
At the time, Memo didn’t know that another archeologist had once decided to re-seal the cave forever. All he knew was that his team
had found another small opening leading down into the earth.
DE ANDA: It's about one meter high—that's like three feet—and maybe another meter wide. You have to crawl from the first time right there in the entrance. And then you continue like that for a long time.
GWIN: Memo and his team crawled into the pitch black cave, the only light shining from their headlamps. He says, it didn’t take long to find signs of people. In a small cave chamber, there was an ancient ladder, made out of stone. And on the ground, there were broken pieces of pottery, like a bread crumb trail leading further into the cave. So Memo kept going, deeper and deeper into the Maya underworld, wondering, “What else is in here?”
DE ANDA: You have to follow where the cave is taking you. And then you get to a section when you're crawling that you are like in a big base of mud. And you feel like the mud it has glue because you cannot move your hands or your knees. Because you're crawling on your knees. And you feel that you get stuck to the mud and you're getting tired and tired and the air, it’s not very good. Right there is when you stop and think to yourself, “How come the ancient Maya come all the way here?”
GWIN: To answer that question, and find what makes this cave special, Memo had to keep crawling. But caves like this are labyrinths. They can go in all directions. And Memo and his team kept running into dead ends for days. Then finally, one day, they seemed to find a passageway that was leading somewhere. But there was a problem.
DE ANDA: There was a coral snake in the middle of the little road where you have to crawl and you cannot move.
GWIN: Wait a minute, first of all this is a coral snake. This is a super poisonous snake. Right. I mean those things can kill you.
DE ANDA: It is very dangerous. Yeah it's beautiful but deadly. And this is why I didn't dare to go through.
GWIN: How far away from you?
DE ANDA: Uh, maybe 30 centimetres.
GWIN: Ay yiy!!
DE ANDA: Yeah! Yeah, I was afraid and I took a picture with my cell phone and I get out of the cave. Show it to our friends and they say, “Well that's very deadly. Don't try to go through.”
GWIN: To some in the Yucatan, a snake can be more than just a dangerous animal. Ivan Batun is an archaeologist at Universidad de Oriente. He studies the ancient Maya and is also Maya himself.
IVAN BATUN (ARCHAEOLOGIST): You have to be in a good way with the owners, the spirit owners of the caves, and cenotes.
GWIN: Ivan says every cave has an owner, and the owner can take different forms, including as a snake. Even today, he says, many Maya people say you have to ask permission from the cave owner to go deep inside.
BATUN: You don't ask for a permit, you don't safe to be there. Accidents can happen. I mean, in going into a deep cenote or a deep cave is dangerous for everybody. You know, anything can happen. But the thing is that if something happened, people believe it’s because you don't ask permit.
GWIN: Maybe the coral snake was protecting what was inside.
BATUN: The water from the caves especially the water in the deep on a cave or coming down from the stalactites—like, they are dripping water all the time—that is believed to be the most sacred water.
GWIN: Ivan says the Maya still use that sacred water in special ceremonies.
BATUN: And yeah, I mean, there is people who still believe that Chaac is the one who is actually living in cenotes because he is the god of water and rain.
GWIN: The Maya had a lot of gods. But for this story, you only need to remember one. Chaac. He’s the god of water and rain, key resources for any civilization. And so when the Maya needed to get closer to Chaac, they headed to the cenotes.
ROMEY: There is no surface water in Yucatan. There are no rivers. There are no lakes. There are only sinkholes. All of the water is under the surface of the peninsula. And the only way to access that water is if you're lucky enough that the surface has opened up to enable you to access the water.
GWIN: The rise and fall of the ancient Maya: it seems to come back to water. Kristin Romey says archaeologists are still trying to figure out why the Maya abandoned their cities.
ROMEY: But we do know that a decrease in rainfall had a huge impact.
GWIN: Because without rain, how can you grow food? And in the Yucatan, Memo says,
when the Maya prayed for rain, they didn’t only look to the sky.
DE ANDA: Water is the source of life. Water is in the underground. Water, it's needed for agriculture so they needed rain, they knew rain come from caves. So the cave is part of their symbolic religious-social system.
GWIN: So when a coral snake inside the cave blocked Memo from crawling any deeper, the Maya members on his team knew exactly what was going on.
DE ANDA: The Maya said, “This is another spirit. This is the guardian of the cave and he is not happy with you going in there. So let's do a ceremony and ask for a special permission.” And after five days the Maya said, “Yeah the snake, it's gonna let you go through.”
[sound: Maya ceremony]
GWIN: A shaman came to the cave And asked for protection from Maya gods. But he also asked for protection from Catholic saints, and for the spiritual owners of every cenote in the area. And then, Memo headed back into the cave. There was just one other person with him—
a videographer named Karla. Together, they crawled all the way back to where he had been before.
DE ANDA: The problem is that when we tried it again the snake was still there. So after all the ceremonies and all that, I said well I'm going to close my eyes and go through. And then I go through.
GWIN: Memo made it past the snake. Then he turned around to help Karla get through.
DE ANDA: She said no, if there is a snake there I am not going to go through. So I said, “Well don't worry, I'm going to go for 30 minutes, see what it is like, see where it’s going through, and I'll be back.” But the cave just allowed me to go in more and more. And I just forget about time.
GWIN: So when you're inside like as you move through the passages and it opens out into different chambers, what is that feeling like?
DE ANDA:You feel that you are trespassing a very sacred place. You feel that you don't belong there. But the cave is like calling you. It's calling your name. And you say “Well, just a little bit more. I'm going to go just to that little crevice or that stone 20 meters away from me.” And then you got there, you see more passageway, you say just a little bit more. It’s like a mermaid singing and telling you, “Come in, come in a little bit more.”
GWIN: Memo told Karla he’d be back in 30 minutes. But he couldn’t stop himself. He kept crawling, following where the cave took him. And then finally, Kristin Romey says, all that crawling paid off.
ROMEY: I think a less determined archaeologist might not have made the discovery he did because he literally crawled on his stomach for about 2 hours. He said after about two hours it opened up into this chamber and in the chamber were just dozens and dozens of untouched incense burners. Maya incense burners that still had charcoal in them. It was like the Maya had just left a day earlier.
DE ANDA: Not only untouched but there's a lot of it. There is over 200 incense burners. The degree of preservation is great.
ROMEY: Untouched to the point where you have stalactites and stalagmites growing over the incense burners.
ROMEY: Yeah. Literally, he was probably the first person in there in, what—1,000 years?
GWIN: Memo knew right away, this was an extraordinary place. But it would take a lot of work to understand what it all meant. And before he could start, Memo had crawl back to meet up with the rest of his team.
DE ANDA: Karla was very concerned. Because she said, “Memo, you were gone for three and a half hours, and you said you were going to keep going for 30 minutes.” But I was so thrilled actually when she asked me what is there, what took you so long, why you went so far—I started crying. I just couldn't control myself and start crying and say well this is one of the most amazing places I have been in my whole life.
GWIN: When Memo told his Maya coworkers what he found, they knew right away what it was. This was the Cave of the Jaguar God. A cave they had heard about, but only as a myth.
DE ANDA: Yeah this cave is called Balamku. Balamku means the jaguar god. Jaguars were sacred. They were animals that were believed to be able to one of the very few animals that could go safely into the underworld and come back.
GWIN: Memo just found Balamku last year, and he says they still have a lot of work to do.
DE ANDA: We want to set a model of research in Balamku. A model of archeological research in Maya caves. So we will take our time.
GWIN: He says they’ll be excavating Balamku for at least five years. One of the first things he noticed about those incense burners was that the people who made them were worried about water.
DE ANDA: They are trying to get probably to the rain god to ask him, “Please we need rain. Because they are having big troubles on the surface. I mean it sounds—it looks—like there was a big drought and they needed rain desperately.
GWIN: Remember Chaac? The rain god? Looks like a thousand years ago, he wasn’t giving Chichén Itzá the water it needed.
DE ANDA: What we see in the incense burners, what we see in most of the iconography of the ceramic pots is that there is a foreign God there. It is not Chaac, it's Tlaloc. The the central Mexico rain god.
GWIN: Memo doesn’t know yet why the ancient Maya in the Yucatan were praying to a god from Central Mexico.
DE ANDA: There could be several reasons. There could be an influence from central Mexico. There was people from central Mexico doing this. Or, they are so desperate that they believe Chaac have abandoned them and they are praying to a different god to try to create rain. So we don't know that for sure yet.
GWIN: Memo says this cave has so much to teach us. And to make sure he doesn’t miss anything, he’s bringing a whole arsenal of high-tech tools to Balamku. First, his team is making a 3-D model of the cave. They’re also looking for human remains. If they find bones, or teeth, they’ll run a test that could pinpoint where exactly that person grew up—like a birth certificate for someone born a thousand years ago. None of that would have been possible in the 1960s when that first archaeologist re-sealed the cave.
GWIN: So why do you think he decided to seal it again?
DE ANDA: That's a big question that we don't understand. Unfortunately he's dead. It could be for many reasons, one of them being he felt it was too much of an enterprise for the time. Maybe he didn't get enough budget. Maybe he was very busy there was not a lot of archaeologists back then. Y’know, it’s hard to understand. Some of our Maya friends said he was afraid of the cave because he thought it was a curse or something. But this is just a rumor. I really don't know what happened there, Peter.
GWIN: It’s a mystery. But for Memo and his modern tools, it’s also a blessing.
DE ANDA: It will tell us the moment of the starting of using of the cave and the moment of the termination ritual. So that will tell us very likely the story of Chichén Itzá. Because we believe they started using the cave when they first arrived to Chichen, and they start building Chichen. And they stop using it when Chichen collapsed.
GWIN: Because the story of Chichén Itzá isn’t just about the ruins of an ancient civilization. It’s also the story of what’s beneath it. And an underworld that contained the Ancient Maya’s most precious resource: water. More after the break.
GWIN: The pictures and video from inside the Cave of the Jaguar God are crazy. They show you just how tight these passages are that Memo had to squeeze through. You can see pictures of the cave and the incense burners that stunned archeologists at the link in our show notes.
Also, read about other ways Memo is investigating Chichén Itzá. He’s using ground-penetrating radar to find new, undiscovered passages to the underworld. And, one other mind-bending thing his team has found: the world’s longest underwater cave system. 215 miles long, underneath the surface of the Yucatan. It’s a watery abyss down there, but they’ve found the remains of ice age animals like giant sloths and an ancient relative of elephants. More details in your show notes, right there in your podcast app. Overheard at National Geographic is produced by Jacob Pinter, Brian Gutierrez, and Robin Miniter. Our senior producers are Kristen Clark and Jinae West. Our editor is Ibby Caputo. Michelle Harris fact-checks our episodes. Our Deputy Director of Podcasts is Emily Ochsenschlager. Hansdale Hsu composed our theme music and engineers our episodes, with additional help from Nick Anderson and Interface Media Group. Special thanks to: Carmen Graterol and Karla Ortega. Overheard is a production of National Geographic Partners. Whitney Johnson is the director of visuals and immersive experiences. Susan Goldberg is our editorial director. I’m your host, Peter Gwin. Thanks for listening, and see y’all next week.