Explorations
Text: Ari Lannoy, from the book "Le Domaine des Grottes de Han, une aventure humaine" (The Domain of the Caves of Han, a human adventure) by Albert Joris.
Of Man and Cave… Yes, it’s a long story but it’s a story I relish telling because I know it so well. In a way, it’s my story. Over the course of these lines, I will try to convey the great adventure that was the exploration of the bowels of the hill. And, as we say in caving, “there’s more cave to explore!”
My name is Ari Lannoy. I was born in 1987 and ever since... I’ve been roaming the Cave of Han! Both my parents were cave guides, so I often accompanied them on their tours or during their caving expeditions. My connection to the Cave goes back even further, as my family have been tour guides there for the past seven generations. Since the 1850s, we’ve led groups of visitors, generation after generation. Today, the Cave remains my favourite playground. I observe it, study it, and explore every nook and cranny of this stunning underground maze… But let’s start at the beginning!
The first steps...
The oldest human traces found in the Cave are pieces of charcoal dating back circa 10.500 years. These fire remnants were discovered in the galleries closest to the surface. At this stage, it’s more about habitation than exploration, as exploration implies the intent to discover the entire Cave network.
Over time, the function of the Cave evolved: it served as a refuge, a sanctuary, or even as a hideout for a gang of bandits. Numerous traces of human presence have been found in the riverbed at the place known as the “Trou de Han.” More information about archaeology is available!
The Abbot of Echternach, Jean Berthels (1544–1607), was the first to write about this cave “frightening to behold, at the edge of the Duchy of Luxembourg, not far from Rochefort, in the village of Han-sur-Lesse.” Shortly after, in 1608, it appeared on a map for the very first time.
Descriptions, accompanied by the first illustrations, began to flourish from 1743 onwards. At the time, we have the same knowledge about the entrances and galleries as our forebears, thousands of years earlier, perhaps we know even less… There is still so much exploring and mapping to be...
The first great discoverer
In the 18th century, the wealthy travellers who had the leisure to explore probably relied on local villagers to guide them through the approximately 300 metres of galleries near the Trou de Han. What a thrilling expedition it must have been to enter the gaping, dark hole by boat, solely lit by the glow of torches!
In 1809, a tourist from Ghent arrived in the village. He suggested to his guide, the village miller Jean-Baptiste Remy, that it would be a good idea to start a visitors’ register. This marked the unofficial beginning of organised tours of the Han Cave – quite an event!
Eight years later, during a visit on 6 August 1817, the same guide, Remy, made the first connection between the Trou de Han (the Cave’s current exit) and the Trou d’Enfaule on the other side of the hill, enabling the very first full crossing of the Han Cave.
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The age of science
In 1822, Jean-Baptiste Remy participated in new discoveries However, this time, the approach was entirely different. It was no longer about tourism but about genuine scientific exploration. Two scientists from the Brussels Academy of Sciences, Kickx and Quetelet, enlisted Remy’s help to explore all of the caverns crisscrossing the Boine Hill and then create a detailed map. Over 200 metres of galleries were discovered and added to the network owned by Mr Gille, the Cave’s proprietor. Kickx and Quetelet published the first map of the Cave, detailing 1.367 metres of galleries. This sparked an enthusiasm for exploration that continues to inspire countless cavers to this day.
Six years later, Dr. Joseph Alleweireldt, a physician, explored the Cave with the guide Mr. Vigneron, aiming to document every access point and passage in detail. Over the course of these explorations, Vigneron himself discovered 457 metres of new networks, which are still visited today. These include the Vigneron Hall, the Precipice, the Frog Gallery, the Fox Hall, and, at the end of the path, the Scarab Hall — animal-themed names for this chapter of discoveries!
In subsequent years, the guide Marée discovered a small chamber that enabled a complete reversal of the tour route in 1857.
True adventurers
By now, you’ll have realised the crucial role guides played in the history of the Cave’s exploration: Remy, Vigneron, and Marée not only guided visitors but also made groundbreaking discoveries. And it didn’t stop there! The 1850s were pivotal in the Cave’s history. During this period, Pierre Lannoy became the chief guide, also known as the “head conductor.” In 1856, the entire site (surface terrain and underground areas, including the Cave) was purchased by Edouard de Spandl, who launched the Cave’s destiny as a show cave.
In 1858, almost 900 metres of galleries were discovered. On 16 May, the priest Ambroise Jaradin—passionate about the Cave—and Henry Remy (son of the 1817 miller-guide) crossed the Styx and discovered the Capitol. Nine days later, on 25 May, Jaradin, along with Mr Pochet (a teacher), Mr Lannoy (a cave guide), and Mr. Charlier, entered a small crawl space in the Vault. This led them to a gallery 584 metres long, culminating in what was then considered the Cave’s crown jewel: Les Mystérieuses. The explorers were awestruck by sheer beauty of their discovery. Alas, this remarkable site would have to remain inaccessible to most ; the Adventurers’ Gallery was far too challenging for the average visitor. The group etched their names in a mud embankment, and, using candles they’d saved for their return, made their way back to daylight, giddy with delight and their heads overflowing with memories.
The next day, Pierre Lannoy returned alone from the other side. Via the recently discovered Styx and Capitol, he reached the Lannoy Gallery, which led him directly… to Les Mystérieuses! A day earlier, it had seemed so unreachable, but this new access point made it far easier for visitors to admire.
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A Family History
Pierre Lannoy was my great-grandfather’s great-great-grandfather. Since his lifetime, generation after generation of Lannoy family members have succeeded him as tour guides leading visitors through the marvels of the cave. In other words, starting with him, I am the seventh generation of guides and explorers that have the privilege of roaming the Cave of Han!
I have always wondered about his discovery. Was it pure chance, luck, or did he and his companions realise the significance of their location the day before? Could he have had an intuition that it was possible to return to their discovery from the other side? Did he keep this insight to himself? I will probably never know… This remarkable discovery established a new visitor route that remained in place until 1962!
These events marked, in some ways, the end of the first great era of speleology in the Cave of Han, even though speleology as a formal discipline did not yet exist. After this major discovery, no significant breakthroughs occurred for over a century…
A mysterious… and unpredictable river!
The Boine Massif still harbours so many mysteries…For example, the river that disappears on one end and re-emerges on the other. Where does it go? We can catch glimpses of it here and there in the cave, but these glimpses are only tiny fragments of its underground journey.
In 1933, Robert de Joly, a renowned French speleologist, dived into the Gouffre de Belvaux wearing a diving suit. It was the very first attempt at an underwater exploration and definitely a bold one, even though it did not bear fruit. In 1953, Jacques Théodore and Robert Stenuit became Belgium’s first true cave divers. Using new diving techniques, they tackled two small siphons upstream from the Salle d’Armes (Weapons Chambers) and discovered the Salles Ronde and Ovale (the Round and Oval Rooms).
In 1959, the speleologist Jacqueline Desmons was trapped for 41 hours in the Trou des Crevés. Following a heavy storm, the entrance siphon filled with mud, leaving the unfortunate speleologist stuck inside. Diver Marc Jasinski managed to rescue her by diving into the muddy waters. Later that year, Jasinski resumed aquatic explorations and discovered the magnificent Réseau Sud (Southern Network). Unfortunately, his diving companion, Pierre Brichard, tragically lost his life in the Siphon de l’Au-Delà * — now named in his memory — upstream from the Salle d’Armes. This tragic event, on 12 September 1959, brought cave diving at Han to a halt for several years.
* Au-DelĂ is French for the Hereafter!
The Golden Sixties
As mentioned earlier, the tourist route remained unchanged for 105 years—a record! However, during the 1960s, the Domain experienced an extraordinary burst of activity ! Excavations were happening everywhere, both inside the hills and on the hillside.
In September 1962, the Spéléo Club Verviétois (a spelunking club from Vervier) discovered the Galerie des Verviétois. It linked the Salle Vigneron to the Mystérieuses. Within six months, this 236-metre stretch was prepared for visitors. This was significant as it made the tourist route easier while bypassing the lower levels, that were also quite muddy, and less ornately decorated with concretions.. To this day, it remains the most richly adorned section of the tourist route, which has remained unchanged since 1963!
Another colossal project of that decade was the excavation of the Tunnel, a new access route to the heart of the cave, leading from the Lesse resurgence to the Galerie Lannoy, and passing through the Petites Fontain must have been like at the time!
A totally fabulous Christmas present!
During the winter of 1964, the southern slope of Boine made the headlines once again. At the time, a group of young amateur speleologists and naturalists were studying bats in the Trou Picot. On 26 December, by inadvertently dislodging a rock that then tumbled into the underlying void, they made one of the most remarkable discoveries in the history of Belgian speleology ! Before them lay an immense cave—a succession of gigantic chambers, each more richly adorned with concretions than the last, stretching out over 2 kilometres; they had accidentally discovered the « Grotte du Père Noël » (Father Christmas Cave).
More than fifty years earlier, this very site had already attracted attention. In the winter, when it’s cold and dry outside, warm vapours rose through the rocks, enabling lush mosses to thrive. This was a clear sign that there was a void below—a void finally uncovered as a Christmas gift in 1964 by Deflandre, Vivier, Léonard, Sturbois, and Petit.
The Belvaux Chasm
Another tragic accident struck the cave divers in 1971: on 25 August, Daniel Ameye became lost in the still-uncharted Belvaux Chasm and was never found. This marked the end of cave diving in Han until 1985.
In the meantime, the exploration endeavours continue. From 1964 to 1972, the the Catholic University of Louvain Caving Club (SCUCL : Spéléo Club de l’Université Catholique de Louvain) excavated a gallery opening beneath the Belvaux Chasm’s archway: the Drève des Etançons. After 501 days of work, they finally achieved a breakthrough with the river! They discovered the subterranean Lesse river network downstream of the Chasm. This added a whopping 1,500 metres to the Cave of Han’s network and enabled an extraordinary 800-metre boat ride along the river — unique in Belgium!
In 1987, a diving team headed by Michel Pauwels and Claude Grandmont achieved the feat of crossing the Siphon de l’Au-Delà , 38 years after Pierre Brichard’s death. They navigated several siphons upstream from the Weapons’ Chamber, covering a total length of 372 metres and reaching depths of 32 metres! This connected to the subterranean Lesse river network, already accessible from the other side via the Drève des Etançons. Finally, in 1988, Pauwels, Bastin, and Hoenraet conquered the Belvaux Chasm, a legendary and symbolic 42-metre-deep obstacle. The mystery of the subterranean Lesse was finally solved!
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In the 21st Century
The official map of the Han Caves network, drawn up following recent discoveries, shows 14.248 metres of galleries, by far the longest network in Belgium (the Lorette Cave in Rochefort, the second longest cave in Belgium, measures 6,595 metres). If we breakdown this number, we have 10.693 metres for the Cave of Han 2.115 metres for the Father Christmas Cave, and 1.440 metres for the Trou des Crevés.
On the maps, the Pentecost Hall in the Southern Network is very close to the subterranean Lesse. In November 2019, a junction was made by digging approximately twenty metres deep into the clay. I was one of the happy few that was there on the day this junction was put into place. I was able to directly feel the emotion that swept through the group when, from the other end of the gallery, we heard someone shout "It passes, it's gotten through!" . Needless to say, it was a very powerful moment indeed.
A month later, during my winter work in the Dome Hall, I too made a discovery. Attracted by the sound of water flowing through the rocks, I clambered between the wall and rubble. As you can imagine, I was really excited, and I could hear the sound growing louder, as if it was guiding me. Suddenly, I reached a small hole on an overhang above the river (which was turbulent at that time of year). I was in the Sentinel Hall. And this is how nother new passage was discovered!
161 years after the discoveries made by my ancestor, experiencing this was quite extraordinary for me. Feeling curiosity pulling me towards the unknown, then feeling my heart racing with excitement as I saw it leading somewhere... making my discovery and finally walking back just bubbling over with excitement and bursting with the desire to tell everyone!
It continues!
Marc Jasinski perfectly describes the emotion cavers feel in such a special moment : "For every caver in the world, there is but one magic sentence that encapsulates the hopes, the sheer elation of discovery, the intense joy one can feel underground. This sentence is: 'It continues!' (...) I believe that the human body is made for these wonderful discoveries and for the physical happiness of aligning with these harsh conditions, which for the average person represent a hostile world, an entirely inhospitable world."
I am certain there are still things to discover, and that somewhere, there is more cave to explore!
This text was composed by Ari Lannoy. It is from the book "The Domain of the Han Caves, a Human Adventure" by Albert Joris, which is available for sale in the Domain's shops.
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