A short history of Lao speleology

Discovering the through-caves of Khammouane


“Black marble rocks in Lakhon mountains”

Drawing by E. Burnand, after J. Harmand (1867)

Through-caves are the most outstanding natural wonders of Khammouane.  For immemorial times, lao people have used them as convenient pathways to access remote valleys and villages otherwise impossible to reach. Using poor lightings, lao people have been able to venture miles away from the caves entrances. Their tracks can be found everywhere - foot prints, potsherds, remnants of torches - in the most remote corners. However, these explorations, so present, so vivid, have left little traces in the history of lao caving, at least in its written history.

In Khammouane, this history begins in the middle of the XIXth century, during the exploratory mission led by Ernest Doudart de Lagrée and Francis Garnier (1866-1868). With them, Louis Delaporte will report with his etchings the extraordinary karst landscapes of Khammouane.

To access the tin deposits (at that time believed to be lead) of the Nam Pathen valley, de Lagrée crosses one of the famous Khammouane tunnels, Tham Khong, near Ban Nano...


A few years later, Auguste Pavie, the “barefoot explorer” (1879-1895), explores Laos to define its borders with China, Burma (Myanmar) and especially Siam (Thailand), and looks for routes to connect it with Annam (Vietnam), a rapidly growing French colony at that time. In March 1889, Pavie visits the valley of the Nam Hin Boun and is told that, not far from its spring, the river passes under the mountain, through a cave, while remaining navigable.


The year after, Pavie asks captain Pierre-Paul Cupet to investigate the Mekong’s left bank, between Lakhone (now Nakhon Phanom) and Luang-Prabang. Cupet takes this opportunity to check that the river actually crosses the mountain...


15 March 1889 - Here is the Hin-Boun by which we go towards Khammon-Kamkeut. Since we left I have heard every day praises about its curiosities of nature which made it famous in Laos. I am very happy that my privilege of first-comer gives me the chance to map out its still unknown course. […]

18 Mars 1889 - […] In its lower part, the river banks [of the Hin-Boun] subjected to the floods are covered with fields of indigo, mulberry tree, tobacco and cotton, scattered with villages: as soon as they rise, a rich forest livens it up differently. Of an equal flow, because of the lack of sizeable tributaries, neither deep nor wide, it roams between islands of uprisings of naked, ripped limestone rocks, dark coloured, appearing in cliffs, often reaching about 300 meters in height, which it strikes and eats away, sometimes on a bank and sometimes on the other, where eyes perceive deep caves, vast chambers the walls of which swarm uncountable masses of bats which accumulate a thick manure, a fertiliser of the nearby grounds. […]

The accumulation of tortured rocks poking out everywhere, far from saddening it, adds to the view in each of the bends an illustration so incomparable that we sail away from it with regrets.

Seeing us fully charmed by this nature of central Laos, and themselves excited, some boatmen jump on the bank, and collect those flowers that have the discreet and inexhaustible scents that they know as more than rare. While offering them to us, smiling, they say: “Jewels of one day of the Hin-Boun banks, all this is nothing ; our ground contains gold, tin, and gemstones with sparkling colours the value of which we hope to learn from you soon. Go towards the springs, you will be charmed: because you will travel with the river under a mountain which it carves and crosses while remaining always navigable !”

Pavie A., 1919. Mission Pavie, Indo-Chine, 1879-1895. Géographie et Voyages, VII. Journal de Marche (1888-1889), Ed. Ernest Leroux, Paris (1919). pp. 259-261.

Auguste Pavie, in Laos (1893), then in Paris (1905)

On Pavie’s map, the underground course of the river is already indicated. Also mentioned is the village of Ban Thonglom, which will accommodate our team in 2011 and 2012, in search of the “deep caves”, rich in phosphates, mentioned by Pavie.

The crossing of the Hin Boun river cave - 1890 
The visit of Tham Heup - 1902
The exploration of the Xe Bang Fai cave - 1905 
The “Marie Cassan” exploration - 1948 
The modern era - 1991-... Tham_Konglor.htmlTham_Heup_1902.htmlXe_Bang_Fai.htmlMarie_Cassan.htmlshapeimage_4_link_0shapeimage_4_link_1shapeimage_4_link_2shapeimage_4_link_3
The crossing of the Hin Boun river cave - 1890 Tham_Konglor.htmlshapeimage_5_link_0

De Lagrée travel and localisation of the Ban Nanho through-cave

Ernest Marie Louis Doudart de Lagrée

Facing Lakhon rises a range of limestone mountains whose peaks, oddly cut, strongly contrast with the azure sky. No field ripple announces this massif in the middle of the plain. Under the strong pulse of some subterranean force, the marble rocks have found their way through the ground without bending it and have piled up on top of each other to form a group of the strangest appearance.

Two members of the Commission, Mr. Joubert and Mr. Thorel, went to visit these unique mountains among which are found deep caverns; natural circuses, formed by marble walls with hundreds of meters of height, limestone needles, appearing as columns in the middle of the plain and remotely resembling the gigantic ruins of some pelagic temple.

[...]March 7-12, 1867 - There were reports to Mr. de Lagree of lead mines operated by the natives about twenty miles of Houten. He departed [on March 7] with Dr. Joubert to visit them, desiring to see for himself the nature and value of this deposit. The two explorers sailed up the course of the Hin Boun for two days and landed on March 8 on the left bank of the river near its confluence with the Nam Haten, an unnavigable small tributary, of which they followed the valley.

On March 9, close to the village of Nanho, they crossed a cave nearly 400 meters long with a height of 30-40 meters, whose walls were formed of a gray marble veined with black. They had arrived in the area of the lead mines.

[...] On that side there is no communication with the Tong King, whose valley of Hin Boun seems separated by a long mountain range. The metamorphic formation already observed in Lakhon seems to predominate throughout the region whose marble caves recall the famous caves of Touran and undoubtedly belong to the same geological era.

Garnier F., 1885. Voyage d’exploration en Indo-Chine. Hachette, Paris. pp. 228-230.