The next morning, after a light, in-room breakfast, we packed a small bag for the walk to the caves. There are paths at several levels, but they all converge at two set of steps up to the base of the headwall. Our path started to the left of the buses parking, and to the left of a large, 2-storey building containing the Visitors' Baños. The trail is well maintained and pleasant. About halfway, there is a large and interesting tree.
The bizarre shapes of this contorted tree may give rise to lurid thoughts in fertile minds. Keep your head down and your mind clean when walking by the tree. Near the base of the stairs to the caves are a gift shop (open when we were there), a cocina económica (open on weekends), and a guard. The stairs lead under a small, lush tropical garden growing on tufa rock. The tufa is evidence of limestone charged waters that once flowed over the slope, but is now dry.
I first read of Las Grutas de Tolantongo in the Association for Mexican Cave Studies Newsletter back in the late 80s. Mexican and US cavers attempted to traverse the cave in an upward direction, but were thwarted by the heavy water flow as well as the enervating heat. Later, attempts to traverse the system, from the sinking stream at La Gloria, a canyon upstream of the headwall, were successful I think the price paid was dire, with at least one person losing their life, but I am not at all sure about this. Dr. George Veni, a Texas caver and hydrologist did a study of the caves but his report has never been published. In an email to me, he wrote that the thermal waters originate at some distance, where they sink along the limb of a syncline, to a depth of 2.2 kilometers.
The head of the canyon resembles a movie setting. There are numerous falls of water, large and small, dropping over the cliff faces and falling as lacy curtains in front of the two cave entrances. A rougher set of steps goes up on the left to the smaller entrance of the steaming thermal cave called "El Túnel".
The rules of the resort require that all persons entering the cave be in bathing suits, and sober. Other than those rules, anything goes. You can take your little kid in with you.
I'd already changed into swimming trunks back at the room, and in front of the caves put on wading shoes. I also had a water resistent headlamp, but except for the Túnel, it wasn't really needed. If you wear glasses, it's best to remove them.
I have been in hundreds of caves over the years, both "show" caves, develped for the public, and "wild", undeveloped caves. I'd never seen any like these. At the top of the rough steps, I grasped a handrope and got a cold and invigorating shower from the curtain of water falling over the entrance. Immediately upon stepping into the rocky bottomed stream, I could feel the warm flow of water. The Túnel is a tube about 2 meters in diameter, with the walls heavily decorated by small dripstone and flowstone speleothems. Here and there, substantial spouts of very warm water jet out of the ceiling where it meets the walls.
Once in again, I advanced about 100 feet to the edge of a deep pool. A small family was sitting on the edge. I asked how deep it was and the man made a gesture up to his chest.
Hmmm... a rope loop tied through an stalactite eyelet was an aid to crossing. Although El Túnel is said to penetrate the canyon wall for 100 meters, I decided that age had taken its toll and that I'd seen enough.
After another refreshing shower, I girded up for a visit to the main, lower Gruta. There, the near full force río rushes down some 2 meters into a narrow canyon cleft. Down in the cleft, a whirlpool traps swirling inflatable buoyancy devices, balls and the like, a good warning to visitors to stay out!
The actual entrance to the lower Gruta, while a bit foreboding, is really not difficult. Mamás e hijos were lolling on the semi-submerged sandbags just inside. I crossed the current, grasping the provided hand rope, and had no problems. I was in the cavern, about crotch to waist deep in warm water, awed by the thunder of the central waterfall gushing from the ceiling. It was at least 4 times the force of the smaller spouts seen in El Túnel. The floor is mostly coarse gravel where it is clear of rockfall and sandbags. (I suspect that the ejido has bulldozed the floor level, and possibly "improved" the cavern, but I can't be certain.)
The interior of the Gruta entrance cavern is almost all within the "twilight zone" of sunlight,, dimly lit toward the back, but no artificial illumination was needed at the time. (mid-morning) I would say that after the sun goes over the peñon, a light would be a good idea. A light is definitely needed to enter el Túnel for more than a few yards.
After enjoying a gentler hot water spout on the right hand wall, I found a semi-detached handline leading to a side passage on the right from which cooler waters flowed. This is probably the conduit for water sinking in La Gloria Canyon. (The one that turns the río mud brown and delivers half-cooked livestock pot au feu in the rainy season.;-)
I had no exploraratory urges to cause me to go up that passage.
Then, after exploring the back wall of the main cavern, with another, excellent hot water back massager, I turned my attention too the main cascade. I'm not sure if I recall correctly, but that cascade may be the one first attempted by cavers in an upward, "through trip" recon. At any rate, when some Mexican jóvenes got under the cascade, I gained heart, and joined them. The force of the water is a knee doubler; powerful and memorable experience.
I exited the cavern, dressed, and we walked back to the hotel.
Later, we descended those 138 steps again, to have lunch at la cocina económica near the swimming pools.
Supper was again eaten on our balcony, listening to and watching the río.
Las Grutas de Tolantongo are in my top ranked Mexican Natural Places to see. The fact that a comfortable hotel, and other visitor oriented amenities are there doesn't detract from it one bit for me. Campgrounds are designated (but barely developed) and you can even rent modern camping tents and other gear from the store at the base of the steps. (I don't think anyone will need at sleeping bag there, at least not from March through October.)
More Photos of Tolantongo and Ixquimilpan Here