Grutas Tolantongo: The Cave, the Steam Tunnel and the Pools
Six named places sit inside this canyon and they are not variations on each other. One is a cave you swim into. One is a tunnel that behaves like a steam room. One is a river. Here is what each is, and roughly what it asks of your day.
Why the water runs turquoise
The colour comes from lime and magnesium released by the rock the springs pass through, according to the operators who bring people down here every week. It is a mineral load, not algae and not dye, and it changes with the weather. After heavy rain, currents coming off the mountains can turn the river brown for a stretch of days. It settles when the rain does.
The same minerals build the terraces. What looks like poured concrete around the pools is travertine, limestone the water has laid down itself over a very long time.
Paraíso Escondido — the pools on the cliff
More than forty thermal pools, stepped down the canyon wall on their own travertine terraces, each one spilling into the one below it. This is the view in every photograph of the place, and it is where most of a day here is spent. One of the pools is fed by a slide. The lowest sit level with the treetops, with the canyon dropping away past the lip.
Getting down to them means a long flight of steps, wet the whole way. Coming back up at the end of a day in hot water is the part people underestimate.
The main grotto — where the river starts
The cave the river rises in. Inside there are stalactites and stalagmites, a waterfall that falls within the cave itself, and a horsetail cascade at the mouth. You get in rather than walk in: the water is warm and you swim through it, which is why every operator on the road puts water shoes at the top of the packing list.
Weather closes this section from time to time. When the river runs high the operators re-plan the hours into other parts of the valley rather than shortening the day.
The Túnel de Vapor — forty metres at forty degrees
A forty-metre tunnel held at around 40 °C by the rock itself. It works like a natural steam room, and it is the thing first-time visitors describe afterwards more than the pools. You wade rather than walk, in low light, with the heat rising off the water.
Take nothing in you would mind losing. Phones do not survive it without a sealed pouch, and there is nowhere dry to put anything down.
The thermal river and the suspension bridge
Below the terraces the river runs opal turquoise between white boulders, warm, wide enough to sit down in and shallow enough to cross on foot. It is the part of the canyon people stay in longest, and the easiest place to spend an unplanned hour. Above it, a footbridge is slung across the Túnel del Paraíso, with the pools underneath and the canyon falling away on both sides. A restaurant area and a zip line sit on the same stretch.
The zip line runs close to two kilometres across the valley and is described by the operators as the longest in Hidalgo. It is in no tour fare and costs about 200 pesos on the day.
Las Pocitas — the shallow pools across the valley
A separate set of built, shallower pools on the far side of the valley, reached either by shuttle or by a walk of about twenty-five minutes. There is a pool with a slide, a second suspension bridge, a grotto with water in it and another zip line at extra cost.
Because it takes a deliberate decision to go, it is quieter than the main terraces. On a busy Saturday that is worth the walk on its own.
La Gloria — the other valley
Further up, La Gloria is a distinct section with its own thermal pools, waterfalls and viewpoints, including a river source and a pool six metres across. Most day trips out of Mexico City never reach it; two of the departures listed here are built around it instead of the main terraces. It is the quiet end of the canyon, and travellers who have seen both tend to name it as the part they would go back for.
How long each section realistically takes
Time on the canyon floor ranges from about four hours to seven depending on which departure you book, and this is what that time has to cover. The table is a planning tool, not a timetable — the walking between sections is what people forget to count.
| Section | What it is | Getting there | Plan for |
|---|---|---|---|
| Paraíso Escondido | 40+ cliff pools on terraces | Steps down from the road | The bulk of your day |
| The main grotto | Cave, river source, inner waterfall | Walk in from the river | An hour, longer if it is quiet |
| The Túnel de Vapor | 40 m tunnel at about 40 °C | From the river level | Twenty minutes is plenty |
| The thermal river | Warm turquoise river, sit-down depth | Along the canyon floor | As long as you let it |
| The suspension bridge | Footbridge over the Túnel del Paraíso | Above the pools | Minutes, plus the photographs |
| Las Pocitas | Shallow built pools, slide, second bridge | Shuttle, or 25 minutes on foot | Half a morning |
| La Gloria | Separate valley, pools and waterfalls | A departure that goes there | Its own trip |
| The zip line | Close to 2 km across the valley | From the bridge area | Queue, plus 200 pesos |
Four hours or seven — the difference is the whole day
The departures split on exactly this. Some give you the pools and one cave. One gives you seven hours, which is enough for all of it without choosing.
Which sections you actually reach is decided before you book, by the departure you pick. The options are set against each other at Grutas Tolantongo Tours, and the map of the canyon shows how the two valleys sit relative to one another. For what a fare covers and what you pay for down there, see hours and access.