Trip Report



 Text © 2006 by John & Susy Pint  -   Photos © 2006 by their respective owners

Updated November, 2013

Photo: Chris Lloyd

On Friday, Dec. 9, 2005, Chris Lloyd and John Pint drove from Guadalajara to Mexico City to visit some of the extraordinary lava tubes in the area. It is truly amazing that there is still no autopista directly linking the two biggest cities in the country, but we managed to get off track (we won’t say lost) only once.

It was most pleasant to exchange stories with Ramón Espinasa, Mexico’s great caving pioneer, over several beers. You may be able to sample the flavor of the stories (if not the beer) in the Interview with Ramón that accompanies this report.

Next morning we woke up Vicente Loreto by telephone and he promised he’d be right over in a half hour. Of course, we doubled that figure and soon were joined by Vicente along with “Yesica-Yasmin.” We then drove out of Mexico City toward Cuernavaca.

The Cuernavaca highway took us straight to prime cave country. “Over there,” said Ramón, who was now truly in his element, “you can see Chichinautzin Volcano which is the source of many of the lava tubes in this area. The name of this volcano means Lord that Burns which suggests that the natives of this area must have observed the eruption of Chichinautzin 1000 years ago… and now, on your left, we are passing Cuescomates, a very curious site with seven small volcanoes, the tiniest being only one meter high. Could it perhaps be one of the smallest volcanoes in the world? By the way, when you visit this place, you’ll find several tree molds, which are impressions of trees that were surrounded by molten lava and subsequently burnt.”

To my amazement, I learned that this area also boasts the deepest lava tube in the Americas, which has a mouthful of a name: Chimalacatepec and has a surveyed vertical range of 201 meters. “And on your right,” expostulated Ramón, “you have the highest cave (of any kind) in the Americas: La Cueva del Volcán Pelado, located at 3500 meters above sea level...”

The area between Mexico City and Cuernavaca is home to some of the most famous lava caves in the Americas.

Photo by J. Pint


Of course, we were not going to any of these record-breaking caves. Our goal was a lava tube briefly visited by Ramón’s brother Luis and named La Cueva Pelona (Bald Cave) because its 15-meter-deep skylight entrance is located in a flat, “bald spot” in the forest and is completely invisible a few meters away.




...As soon as we left the highway to look for the cave, we found ourselves in a seemingly endless maze of criss-crossing logging roads. No map could ever have guided us through that labyrinth, but Ramón’s GPS pointed the way and Chris wove back and forth from brecia (dirt road) to brecia until we found ourselves standing at the edge of a very deep, black hole, which I am afraid, a wandering human or cow could easily fall into....

Ramón (the shadowy figure in the upper left hand corner) at the edge of the skylight entrance

Photo by J. Pint


... Another entrance to this cave is a short walk away. At the bottom of an easily climbable depression, there’s an old wooden ladder that might get you down to the floor, eight meters below, or might get you killed...



We preferred not to find out, and used a cable ladder. It's only an eight-meter drop.


Photo by J. Pint



 ...To me, Cueva Pelona’s most interesting feature was its skylight, when seen from the bottom. It’s the perfect backdrop for a dramatic rappel shot.


The skylight and Yesica.-Yasmin. Although this drop is only 15.30 meters deep, it could be made to look like a much more serious cave with the right camera angle.  

Photo by J. Pint


... The walls and ceiling of the Skylight hole have a lot more color than you expect to see in lava tubes and a veritable mini-forest is growing on the floor below...

ack into the darkness after a refreshing breather in the "jungle.".

Photo by J. Pint


....  I thought he rest of the cave was nothing to write to Aunt Sally about, but Ramón stated that this is one of the best examples he's seen of a Master Tube, with superposed levels, rafted balls stuck in upper levels, and especially with the evidence of thermal erosion in the canyon-shaped passage between the main entrance and the skylight entrance.  He says that for a cave geologist, or anyone interested in Lava Tube genesis, this is a VERY INTERESTING cave, for which reason it will be included among the Post-Symposium excursions

Chris Lloyd measuring a possible lead.

Photo by J. Pint


..Lots of holes were checked for leads but they were either dead ends or required a climbing pole or bolts to be followed, so the survey only produced some 250 meters of passage.


Vicente Loreto escapes from a lead which led nowhere.

Photo by J. Pint


...We exited the cave near sunset, with stomachs growling. This noise was soon stifled by potato chips, canned oysters and beer...

Vicente was in such a hurry he couldn't bother opening the can, but gave it his "vampire bite."

Photo by J. Pint

 ...We then proceeded to the home of Ramón’s parents for yet more beer and lots of caving stories, as Ramón Senior is also a caver and was responsible for getting Ramón Junior interested in crawling into dark and muddy places (see that Interview for more details!).




Some lava tubes are nothing more than long, barren tunnels, half-filled with jagged chunks of black basalt. Iglesia, however, is a wonderful and delightful place where there is always something interesting or beautiful to see, every step of the way.

“We heard about this cave thanks to a rather ordinary little bug which you would probably squash if you found it crawling out of your bathroom drain,” remarked Ramón. The bug is a kind of silverfish Ramón’s ever-vigilant brother Luis, a speleo-biologist, was hunting for. “My brother’s one of those guys who is always turning over rocks to see if there are any bugs under them,” said Ramón. “If Luis comes to a place full of rocks, he will soon have turned every last one of them over. Of course, he has succeeded in finding a number of new species over the years, so I guess it pays off.”




Much of Iglesia Cave lies underneath the quaint little town of San Juan Tlacotenco. “Iglesia,” of course, means “church” and legend says there was once a passage leading into the cave from the local church in Tepoztlán.. Such a connection has never been located, but one day Luis Espinasa did come upon a small hole in the cave roof and when he stuck his head through it, he found he was looking at the underside of a very large, strong bull.

“This bull was in a small pen,” explained Ramón,  “and when the poor beast heard a voice wafting out of the very ground on which it was standing, it simply leapt straight up in the air and over the wall and went charging all around the town, wreaking havoc everywhere. I tell you, neither my brother nor any other caver was welcome in Tepoztlán for at least a year after what has now gone down in history as the Raging Bull Incident.”

First descriptions of Iglesia Cave state that it is “over 400 meters long,” but when Ramón and his friends began to investigate it carefully, they found over five kilometers of passages, forming a three-dimensional maze which reminds me of exactly what you see when you look at a plate of spaghetti. “To make things more complicated, parts of Iglesia Cave are intertwined with another lava tube system, Cueva Castillo, which logically ought to connect to the Iglesia system, but if such a connection exists, we have yet to find it. On top of that, there is another, even longer cave system not far from here, up the hill. This one is called Cueva Ferrocarril (Railroad Cave) and just happens to be the longest lava tube in the Americas,” said Ramón with a big smile.

Well, by now I was very interested in seeing this labyrinth-beneath-a-town. As we approached Tepoztlán, I was impressed by the deep green of the hills that surround the town and the narrow peaks that tower above it. “This is nothing,” commented Ramón. “We’re in the dry season. You ought to see this place when it’s wet!”

The town turned out to be quite peaceful and pretty and I could see why people from Mexico City love to spend weekends here. Besides the natural beauty of the area, there’s a large pyramid above the town dedicated to the god of pulque and in pre-Hispanic times, pilgrims (no doubt very thirsty ones) came to visit it from as far away as Guatemala. Curiously, no sightseers come to visit the caves sprawling beneath the town, even though these have definite tourism potential.

Of course, the three of us, Ramón, Chris and myself, were the exception and being from three different countries (Mexico, Canada and USA) perhaps heralded a future international cave tourism industry for Tepoztlán. This may be helped along next July when the Twelfth International Symposium on Vulcanospeleology will be held in Tepoztlán (See for more info). Visits to Iglesia and other interesting lava tubes and volcanoes will highlight the event.




We donned our caving gear near the church and wandered down the street. Just ten meters from our parking spot, Ramón pointed to a black slot on the roadside. “That’s an entrance to Castillo Cave,” he said. “Why we haven’t connected it to Iglesia, I just don’t know.” A few minutes later, Ramón and Chris walked to the middle of the road and jumped up and down. “Iglesia lava tube is right underneath us,” they shouted, “and there used to be an entrance right here.”

Photo by J. PintPhoto by J. PintLEFT:

The "iglesia"which gave Iglesia Cave its name



Ramón and Chris demonstrate the exact spot where there was once an entrance to Iglesia Cave.


...We took a right on a dirt road and climbed through a gap in one of the ubiquitous stone walls. The entrance to Iglesia Cave turned out to be anything but impressive, just a little opening about a foot high on one side of a low depression...

You can tell by the mud this guy is exiting the cave, not entering, but it's still the same hole.

Photo by Chris Lloyd


...We slid through on our bellies and wriggled our way down to a room where we could stand up. “In this part of the cave you’ve got to watch your feet constantly,” remarked Ramón, referring to the irregular chunks of volcanic rock that covered the floor. Here, near the entrance, we found shards of ancient pottery as well as complete pots that were obviously placed there recently. “People have been placing offerings in this part of the cave for ages and they are still doing it today,” Ramón said.

Ancient potshards. and a handle on the cave floor.

Photo by J. Pint


We climbed up to a slightly higher level and reached a sort of crossroads. Tunnels were going off in three directions. “Come a bit forward and look above you,” said Ramón. I did so and saw that the roof of the passage we had been in was also the floor of another tube right on top of us, whose presence I hadn’t even suspected. The thickness of this roof-floor was only about 20 cm. In that spot, you could really get an idea how complicated was the maze we found ourselves in. “Remember this spot on the way back out,” said Ramón, who hoped that Chris and I would help him guide people through the cave during the upcoming symposium.

A bit farther on, the walls became much smoother and the ceiling was covered with shiny, frozen drops of lava. The upward-sloping floor was, in fact, a solidified river of lava.

“Wow!” We are actually walking up a lava cascade,” I said.

“Don’t get too excited,” replied Ramón… the good stuff is all ahead of us.”

A few minutes later, we were crossing breakdown again and—of course—watching our feet carefully, when Chris said, “Hey, isn’t that one of Luis’s bugs?” sure enough, the white silverfish was easy to spot dashing across the black floor. In a few minutes, we caught two more for Ramón to present to his brother. Although these were not the first Thysanuras collected in Iglesia Cave, we were later told by the great Thysanura collector himself that these three specimens would come in handy for new DNA studies he is undertaking, whose results we'll find out about at the Volcanic Cave Symposium this summer.

...After a little while, two smooth, glassy “lava benches” appeared on both sides of the passage. Ramón jumped up on one of them and we walked along the passage this way for a long way...

Gutters and benches line both sides of the cave in many passages.

Photo by Chris Lloyd




“Look straight up,” said Ramón and we saw a turkey-size “lava ball” glued to the ceiling. This had originally started out as a rock floating along in a river of molten lava. Later we saw giant lava balls several meters around, which had gotten stuck between the floor and ceiling of the passage.

Photo by Chris LloydPhoto by Chris LloydHere and there we noticed quite a few dripping white or tan stalactites on the ceiling. These were caused by a mineral (probably calcite) leaking through cracks in the roof. These are actively dripping and growing and producing either stalagmites on the floor or intricate, multi-colored, miniature gour pools of surprising beauty...


LEFT: Secondary stalactites

RIGHT: Small gours or rimstone dams


.... We also saw tiny, cauliflower or popcorn-like formations, growing like flowers all over much of the cave. Whether these were volcanic in origin or caused by some secondary mineral, we couldn’t tell. “We’ll leave that to Paolo Forti (the famous cave mineralogist),” we said....

Ramón eyeballing the popcorn. Cos'é questo, Paolo?

Photo by Chris Lloyd


By far the most impressive part of the cave (for me) was the Chocolate Factory. The ceiling drips with shiny, chocolate-colored stalactites and draperies. Chocolate “dribbles” run down the side walls. There are strange little stalagmites that are formed out of dozens of perfectly round little balls. On the walls you can see brown “bathtub rings” showing the height of the last surge of lava through the passage. “By the way,” said Ramón, “you’ve heard of lava benches, but have you ever seen a lava couch?” and he stretched out on a perfectly smooth raised surface just big enough for comfortable sleeping.

Photo by Chris LloydPhoto by Chris Lloyd



LEFT: A lava stalagmite which is all but invisible until you get right on top of it


RIGHT: A lava curtain separated from the wall


Photo by Chris LloydPhoto by Chris Lloyd


LEFT: smaller lava balls make convenient seats.


RIGHT: You could spend hours admiring the lava dribbles of Iglesia Cave, which, we suspect, will someday replace ink blots for the  Rorschach test... What do you see?


It was hard to turn around to leave this amazing cave, but we had run out of time, having spent a good four hours looking at everything. “Don’t worry,” said Ramón, “it’s only a half-hour’s walk to get back out. But I’ll let you two show me the way.”

Well, without a GPS, I’m notoriously disoriented, but Chris did a good job of leading us back. Naturally, there were a few places where Ramón just sat and smiled as we scrambled around, checking various passages above and below us, as well as to the left and right. Eventually, we reached daylight, convinced that anyone—caver or not—is bound to be impressed by this extraordinary lava tube.

John Pint