Introduction to caving: exploring a cave - underground river

Riviere Souterraine01beaba Sports NatureRiviere Souterraine01beaba Sports Nature
©Riviere Souterraine01beaba Sports Nature

In these heatwave days, exploring one of the many caves in the Grands Causses is a top activity! And when that cave is an underground river, the adventure becomes unusual and exceptional!

An invigorating caving experience accessible to all, just 2 minutes from Millau!

An approach to the heart of the Grands Causses


Meet up north of Millau, near Séverac-le-Château. A small stretch of limestone causse, beautiful pastures and a rocky bar that catches the eye… We’re getting close.
The last few meters are on foot across a field occupied by a few cows, along a small stream. We respect the place: in nature, you’re always in someone’s home.

Arrived at the foot of the small cliff, at the source of the little stream, first test: putting on our caving gear. Neoprene suit + neoprene t-shirt + caving suit + harness + helmet and headlamp + neoprene booties. Solidarity between us: pull me up on my collar, hold onto my shoulder, my head won’t fit… I’m hot! We head for a small basin in the spring and take our first dip to warm up before exploring the cave. And it’s already clear that a simple bathing suit won’t be enough!

Well, we’re not the first to have found the area nice! A Roman water well-tank feeding canaules for watering the land shows its remains… and demonstrates that the site had been known for a long time! Final equipment check and announcement of the local underground weather: 12° dry in the cave, 8° for the water in the underground river. Not even afraid!

Did you know? There are 4 “Grands Causses”: the Sauveterre, Méjean, Noir and Larzac, these 4
high plateaus stretching between Aveyron and Lozère.

The ABCs of caving

Let’s start exploring the cave and underground river! The entrance is a mousehole but very quickly, we learn to “advance Egyptian-style” as the fissure is so narrow. Can you imagine? Luckily, our guide gives us the technique and we’re on our way!
Coming out of this narrowness like uncorking a good bottle… here we are in the total darkness of the cave, in a first large room where the sound of the underground river can be heard. A strange sensation and an impatience to discover more. Does it sound like a torrent or a waterfall or what? My imagination is on the way!”

After the Egyptian-style walk, the “rolled cake”, an ingenious, effortless and very playful method of crossing between 2 gigantic, very low, horizontal halls… like in a letterbox… and like a letter in the Post Office! That’s it, our feet are in the water and we’re back in a vertical position to progress through the cave! What follows is a wall of concretions which a beautiful underground waterfall jumps over. So that was the big rumble we heard at the start… Assured by our guide, we climb the waterfall, from potato to potato. An invigorating climb through the eddies!

The high plateaux of the Grands Causses boast several hundred caves, avens, gouffres, abîmes, etc… A real Gruyère! sorry… a real Roquefort! Only 3 caves are open to the general public: Grotte de Dargilan, Aven Armand and Abîme de Bramabiau.

Nuggets in the underground river

From the top of this waterfall, the route leads from “piscines” into narrow corridors, in the bed of the underground river. It’s a sight to behold! The pools of giants, larger or smaller, deeper or shallower, but always with a perfect circular shape, as if traced with the compass of our childhood! Water and pebbles must have swirled hard to hollow out and sculpt these natural beauties! Some giant potholes are exposed and serve as a conduit for us to climb. Mineral elevator! Others are flooded and, in the light of the headlamp, offer magnificent reflections and colors. Spectacular!

The underground river gets wider and wider… and deeper and deeper. It’s time to swim the fastest 100m of your life! The water here is 8°C… we say thank you to the neoprene! And at times, the underground river becomes a lake with transparent water and colors… wow!!
Unbelievable emerald or bluish hues. Unfortunately, even protected underground in this cave, the water isn’t necessarily pure. Whose fault is that? The limestone is not a filter. If you do anything at the surface, pollution can pass through the rock to the river

8°C in the water, 12°C in the cave… that’s about the same temperature we see in the
Caves fromagères de Roquefort! They’d make great wine cellars, wouldn’t they!

All the secrets of the underground world

Beyond caving as an activity, it’s a true discovery of the underground world and its specificities that Gilles, our guide, offers us. How about some little critters? Tiny troglobies and cave-dwelling fauna. How about some black traces? The acetylene of “real” speleologists.
Here, clay? how about a mask! On the hands, that’s enough! How about learning to read the gouges in the wall, which indicate the direction of the current and its strength… and therefore the way out?

And what’s that rope in the water? The Ariadne’s thread we now encounter marks almost the terminus of our exploration. After that, there are 13 flooded siphons interspersed with exundated areas, discovered by cave divers… who to this day still haven’t reached the terminus of the cave and underground river!”

The underground river and its giant potholes give way to a fossil passage of the cave. Here, water will no longer pass through. In its place, darkness, the realm of Hades, with crumbling, sharp, black-on-black rocks (a far cry from the outrenoir of Aveyron artist Soulages!).
Striking contrast. A few metres further on: eccentrics looking for their way! mini white stalagtites growing indecisively, at right angles, cocooned, corkscrewed…but what fragility!

The Grands Causses are considered (rightly of course!) as the cradle of speleology after the first discoveries of Edouard Alfred
Martel (1888) and especially with the creation in 1963 in Millau of the Fédération Française de Spéléologie!

Continue the adventure