Opening a legendary system

So, what is the underground network of the village? It is a natural underground grid, though largely modified by Man for his essential uses. It is a system of cisterns, hence providing the village with its most important need: water. In times of a siege, water would have been the most important need of all, as the villagers could not go out in the country, to collect water. Furthermore, the water was important to extinguish fires, perhaps lit by the enemy while the village was under attack.

The entry to this network of cistern is reachable via a room that is located at the bottom of the staircase that goes down near to the old castle. It can also be reached by walking down the path from the main parking lot, past the Tour Magdala, following the old escarpment that lies as a secondary line of defence beneath the actual village on top. At present, the system is carefully shielded by a door and a lock, so that the water supply of the village is safe. But it is clear that this entrance is situated in ancient masonry, attesting to the age of the construction.

In the summer of 1999, the locks were opened. André Douzet and several other curious people would assist with the complete emptying of the tanks, followed by their cleaning. This was no idle exercise: the villagers had reported the purity of the water was not good. Hence, several pumps had been ordered to pump out the water from the reservoir, and endeavour that lasted a few hours. This was followed by pumping out any material and mud that remained behind in the cistern – this being the most obvious cause of pollution. Once this work was completed, André Douzet was allowed to go further down into the system and visit the underground network until the work was officially identified as finished.

We thus had a unique opportunity to explore parts of a network that was identified with the central mystery of Rennes-le-Château. But even before the time of Saunière, it was said that the underground network allowed for private circulation, sometimes by the lords, sometimes by strange visitors, who entered with the knowledge of the Master of the Castle… At the same time, the water level would act as a security – or impediment – of anything that was inside, or someone who would go inside… a natural bank vault door, operated not by high tech codes, but in essence by nature: inaccessible during winter, very accessible during the droughts of summer.

Entering the cisterns

From the locked door, one goes down the steps, to a platform where machines are pumping the water from. There is a small metal ladder going down towards the cisterns. Already, one can distinguish how the system was repeatedly modified, no doubt to accommodate specific needs of the villagers or lords.
Obviously, such observations can only be safely done at times when the cisterns are completely empty. It also meant that we could observe how the primitive tanks had occasionally been refitted, then increased in size. According to the accepted material available, the first system for the storage of water would go back to ancient times. At that time, this would have been a natural gallery, in which water arrived, leading to a type of decorated well, rather than a reservoir as is now the case.
Such a presence would have been a prime indicator for Man that the site itself was a prime means for a sedentary lifestyle, if not an oppidum… and this obviously occurred, as the village and the castle were built. Furthermore, if the well was able to provide water during the summer, that was a major advantage in an area where there is a general problem of potable water in full summer.

With the advent of a growing population, the size of this water cave had to be increased to keep up with the needs of the people. Thus, it is easy to recognise the various installations placed over the centuries. The largest reservoir sits beneath the entrance and the pumps. We can visualise this system as a large natural cavity, to which reservoirs were added. The first one was situated along the “chemin de ronde”, the path leading along the bottom escarpment (from the door, towards the Tour Magdala). The second is located in what we could call the “opposite direction”, in the direction of the centre of the geological plate on which the village sits. It is possible that there was a third reserve, but evidence for this is less clear, as it sits behind a type of partially built up low wall, the purpose of which is not easily understood within a hydrological context. In any event, it is clear that here is a deep cavity, followed by three successive installations in three directions, each with different depths.

Observations on the cisterns

Immediately, let us add the obvious observation that it would have been much more practical to have increased the system in only one direction, in the direction of the terrace, underneath the castle. Indeed, the prolongation of the cistern in the other direction is hardly logical at all. If an enemy was making inroads along the escarpment, he would be able to burst the top of the cistern, which is less than 2 metres below the surface. Thus, he could have prevented or seriously destabilised the flow of water to the besieged. Furthermore, this construction goes all the way to the edge of the cliff. This situation makes it rather easy to dig a large well and see the reservoir empty itself as an artificial waterfall…
It is obvious that these weaknesses could not escape the manufacturers and Masters. Still, we need to ask why the system was thus maintained. It is however clear that the lords either felt totally secure about this insecure system, or had other reasons not to alter its design. For sure, a prolonged siege in the immediate vicinity of the castle would be unlikely. The escarpment could be reinforced.

Rather than debate the theoretical point, let us note that one aspect of the system is seldom discussed: it is indisputable that as the water arrives in the cisterns, once it reaches its maximum level, it naturally stabilises there. In summer, this level is never reached and the question is therefore theoretical in those months. But in winter, the water reservoir does reach its maximum level, without ever overflowing. Somehow, a trigger is activated, but it is equally clear that this triggering device is completely natural… and has never been located. But it means that somewhere, there is a natural fault through which water is able to escape.

The water supplying gallery

From the cisterns leads a gallery, which is the direction from where the water comes to the cisterns. The gallery itself is sufficiently high and broad to allow the easy passage of a man. The direction of the gallery is north-westerly. It is clear that we are inside a natural fault. A type of pavement was cut along the side. As we progress, there are clear traces that sometimes the width was worked on considerably, to leave a convenient passageway. Steadily, the gallery also rises, which is evident as the water runs down from it.
The gallery regularly gets totally inundated with water. The day of our visit, at the beginning of the exploration – at a time the reservoirs had been emptied – the water reached our ankles. By the time we had reached the end of this conduit and us returning from there in a slow progression, the water level was already more than 60 cm high – in say half an hour. Thus, it is clear that the entire system could be compared to a type of siphon, working with low pressure. The length of the gallery is approximately 50 metres, with a regular and accentuated rising slope. The conduit also narrows, before finishing against a type of natural bevel, forming a unit with the native rock. It is here that the water enters the gallery from below and begins its move downwards. As a result, the water here is always lower than elsewhere in the gallery.

In itself, this system is entirely natural and without any great interest, however ingenious it is. But is from these basic observations that will evolve more intriguing and astonishing aspects…

Cistern: entrance from the door

The descent into the tanks

The part of the caves below the escarpment - the normal water level can be identified

A "forgotten" reservoir

Beginning of the gallery

The "pavement" visible on the right hand side

Walk towards the end of the gallery

The end of the gallery, and a profusion of rocks