The Anialarra System has 5 entrances (in 2010) of which this one, AN51, is by far the easiest

Sometimes, snow can remain in the entrance untill the end of August

After a narrow passage, a series of beautiful and relatively easy pits go down... 400 meters!

You just go down, down, down, leaving the rope only once.

Most of these pits are large, easy and dry, only near -150 there is a part where flood water could be problematic.

Near the end of the pits (-387 m)

At a depth of -400 m, one enters a small river (the AN51 inlet). However, in high water conditions, this tiny river can become a raging torrent

A narrow and low passage connects the AN51 cave to the Anialarra System

The further we get, the more water there is

In this part of the cave, the river flows on a steep bed of hard schist rock. It is very spectacular.

The passage becomes bigger and bigger

In fact, there are 3 important rivers joining together. This is Nostradamus River, which can be explored in upstream direction over several kilometers, in giant passages (in average 50 m wide)

Nostradamus waterfall

In the Nostradamus gallery

Very old formations

Notradamus ends after several kilometres in giant rooms (the biggest rooms in the whole cave system). But in the lower parts of these rooms, giant helictites can be admired

It is still unclear if these are gypsum or aragonite formations.

Back in the main drain, going downstream again

For several hours, we follow the river downstream, in a world of water and boulders

Around -550 m, the river cascades a few times on the bedrock

Then, near -575, the floor becomes nearly horizontal for over 1 kilometer! The water is very calm here, but often deep... and freezing cold (only 2,5 ° Celsius)!

The passage remains very big, but the water is still calm

Near the end of the horizontal part

Suddenly, we enter a giant room

After the room, the passage remains enormous. It goes down very steep again, the river is most of the time hidden by boulder collapses

We are now at -640 m where the cave originally ended because of a giant boulder collapse. After many years of work, we got through (in 2005). The boulders go up for over 120 meters. It is an extremely dangerous and unstable passage.

Many boulders have been marked with paint: "DO NOT TOUCH"

We keep on going up and up in this enormous collapse

Finally, after having climbed up Salle Fritz, we leave the boulder collapse

... and we arrive in Salle des Marsipulamis, where we will establish our underground camp.
We have been going in a steady pace for 6 hours now, it is time for a meal.

We change into warm and dry clothes. The temperature in this cave is always below 4° C and that is quite cold! We install the two tents that provide shelter for 6 cavers. The next 3 days we will explore the cave downstream of the camp.

The way on is still upwards! Oh yes: from here on, all passages have been named after famous Belgian comic book characters.

We keep on going up and up, untill we reach a point that is almost 120 m higher than the foot of the giant boulder choke at -640 m.

Here we find one of the biggest rooms of the cave: Salle Gargamel, which is at the origine of the giant boulder choke of -640 m.

Boulders in all sizes.. some of them big like houses.

In the ceiling of the room, many pits arrive. Caves that are still to be discovered!

Salle Gargamel has roughly the size of a football field.

After Salle Gargamel, we go down again and find a giant, fossil gallery: Galerie des Schtroumpfs

It is a splendid gallery, well decorated and with many aragonite formations.

The river must have abandoned this gallery many hundred of thousands years ago.

We are still way too high, if we ever want to find the river again, we must go down. Unfortunately, the only possibility is a 60 m deep series of very narrow pits: Puits des Daltons.

Finally, these narrow pits arrive in the ceiling of a big galery: Lucky Luke Pit.

In Rantanplan, an ancient phreatic maze, developping over 900 m in lenght. Aragonite flowers everywhere.

Rantanplan seems endless. It is also a very unstable area, which has been the cause of a severe accident in 2007.

A very strong and cold airflow has caused these aragonite "tootbrushes" to develop sidewards. Such formations are called "anemolithes".

Again in Rantanplan. Once these galleries where flooded. Touching the wall must be done with care: loose rock ready to fall everywhere!

Suddenly, the Rantanplan galleries arrive near the ceiling of a big room (Salle Sidonie). A 10 m drop takes you down.

Salle Sidonie is about 80 m long. The arrival of Rantanplan, just below the ceiling, is clearly visible.

In Galerie Yoko Tsuno (an ancient lower level of Rantanplan) there are very bizarre formations

This giant helictite (probably made of gypsum) is developping under a 45° angle without touching the wall

The obvious continuation of Salle Sidonie is a very high gallery "Michel Vaillant". There are a few short drops to go down.

Michel Vaillant gallery (after a climb in a complex zone) suddenly arrives in a huge gallery which is almost 50 m high! Luckily, you arrive only 15 m above the floor but it still is an impressive passage. This is the "Castafiore Balcony"

Going down the Castafiore Balcony. One clearly sees the gaping mouth of Michel Vaillant gallery.

After the 15 m drop, we finally find back the river that we lost at -640m, at the foot of the giant boulder choke (over 3 hours away)

The river is called "Captain Haddock's River". It can be followed upstream for about 500 m (heading back to the giant boulder choke), or downstream...

Following the river downstream, the way on is quite complicated but there are some nice spots, such as Salle Nero, very well decorated.

Then, about one hour after we left Castafiore Balcony, the river disappears into another enormous boulder choke. Despite many days of dangerous work, we have not yet managed to pass this obstacle. It is the end of the cave, at a depth of -739 m and at a distance of nearly 6000 m of the AN51 entrance.

But there are other intresting possibilities to explore, such as the big and fossil "Terranef Gallery", 80 m above the actual river bed.

And following Captain Haddock's River upstream, an important inlet is found: it is the Tintin River.

Near the beginning of Tintin River, a very basic camp has been established. Exploring Tintin is such a big undertaking that the "big" camp in Salle des Marsupilami's is way too far

Tintin River can be followed in upstream direction for kilometers and kilometers. At first, it is flowing in quite big galleries (10-15 m wide) and progession is easy.

After about 1 km, a low passage complicates things a lot

At the other side of the low passage, there is a giant room (over 100 m long) "Salle Spip" that you have to traverse

After Salle Spip, Tintin changes radically. It becomes a canyon... going on endlessly, and very dangerous in high water conditions.

It is one of the coldest places in the cave. The water is 2,5°C and the airflow is extremely violent.

It goes on for kilometers like this, gradually becoming smaller and smaller

A trip to the most upstream parts of Tintin takes at least 12 hours (counting from the camp at -600)

On of the branches (Fantasio River) leads to a big and (of course) unstable room: Salle des Flagadas. One of the most remote places on earth...

Tintin becoming smaller and smaller. The most upstream part divides into several small inlets (Quick and Flupke, Fantasio, Rastapopoulos etc..). We are here over 8200 m away from the entrance of the cave.

It becomes more and more unstable and dangerous, loose rock everywhere. . this is the end... but we are less than hundreds meters away from the giant Pierre-St-Martin-Partages cave System (+80 km long) and the water of Partages passes here!