Discovery of Irougou cave, an exceptional burial site in Gabon


An exceptional archaeological cave was discovered in September 2018 in Gabon, in the region of Mouila, by a team of French and Gabonese researchers, announced the authorities on dec 18 2018.

While on a mission for the National Parks, from 18 to 28 September 2018, to survey and search for new caves, speleologist Olivier Testa (NOT Engineers) rappeled down a previously unexplored pit, and set foot in the middle of several hundred human bones, and more than 180 tools, arms, and jewels, in iron, copper and brass. There were also rings, beads, and cowries.
In total, at least 30 skeletons are present.

He explored the bottom of the shaft, took photos of all the objects in-situ, and only a few objects were touched. Olivier Testa left the site as is for future research and nobody else descended since.

Human bones, a sea shell, and currency blades
Iron and copper bracelets, axe head
Irougou cave: iron spatula of unknown form
Forged iron artefact, 70cm long, with two parts, one thin iron disk, the other oblanceolated, linked with an iron rod. This "spatula" has a never described type, according to our research. It might be an iron currency
Iron currency-ring

It is the Minister of Culture, Alain-Claude Bilie-By-Nze who announced the discovery on December 18 at a press conference in Libreville. "We will now have to continue the process and we will partner, of course, with the teams who have already started the adventure. (...) We will accompany the project and the National Museum will be happy to display these objects. "

The geoarchaeologist Richard Oslisly (National Agency of National Parks of Gabon) who accompanied Olivier Testa said "The sepulchral cave of the Irougou is a small wonder. I spotted the entrance of this aven in 1992, but I wasn’t able to go down. "

Olivier Testa continues : these bones would date back several hundred years. More precise dating with C14 will tell. This is the first time such a burial site has been discovered in Central Africa, and this opens up an incredible field of research.
Richard Oslisly adds "This remarkable discovery in more ways than one, is essential to understand the customs and practices of the ancient populations, to appreciate the regional trade by studying the various associated objects and to know, by genetic studies on the teeth of the skulls, what could be the current descendants ".

Some iron object found in the cave
Before realising the nature of the discovery, a few types of the objects were assembled: currency-blades, spear head, axe, gong, and an unknown type in form of a crescent.

The next step will be the 3D laser scanning of the cave to position each object and bone, before careful excavations. This cave offer an incredible opportunity to better understand the dynamics of the population of Gabon.

“In the old times, the dead people were not buried, but abandonned in the forest, recalls Osama. And it was common practice to drag the body at the top af a shaft or a waterfall, and dump it. We thought it prevented them from coming back” reports anthropologist Andersson in 1974.

During the speleological mission, 9 caves with several hundred meters long galleries hitherto unknown were discovered and surveyed by Olivier Testa and his assistant Julie Ikouanga. Hundreds of thousands of bats occupy them, as well as porcupines, pythons and insects by the millions. "It’s the discovery I’ve been dreaming of for a long time," added the speleologist.

The mission was partly funded by Olam Palm Gabon’s Conservation and Sustainable Development Program, which operates the concession where the caves open.

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Richard Oslisly and Maël Ntsinga in Ndongou cave
(photo Olivier Testa)

The Team

The team Oslisly / Testa had already discovered the cave-dwelling orange crocodiles of Abanda, and explored the caves of Lastoursville where they discovered, among many caves, the first cave drawing with ocher and the first first rock engravings in caves of the country (2013).
This is their sixth mission together.

Olivier Testa is a speleologist. In Gabon, after 9 expeditions, beyond Lastoursville and the crocodiles of Abanda (see above), he discovered the first charcoal cave drawings (Nyanga caves, 2007) and surveyed more than 30 caves.
In Haiti, he discovered more than 200 caves among which several archaeological caves with human remains and objects, pre-Columbian cave art, as well as caves with touristic potential.
In Saudia Arabia, he discovered a whole system of very old tunnels under the city of Dumat al-Jandal..
Website Olivier Testa

Richard Oslisly is a geoarchaeologist, specialised in paleoenvironmental studies, and works for the ANPN on archaeological research on the first populations of Gabon. Settled in Gabon for more than 30 years, he is a field worker who knows the whole country. His favourite areas of work are Wonga-Wongue National Park, Lopé National Park and Lastoursville.
He has worked extensively in Cameroon.
Website Richard Oslisly

Julie Ikouanga is a gabonese speleologist, just finishing her MSc in geology and starting a PhD in 2019.
She was Olivier Testa’s assistant for cave exploration and cave surveying. They already worked together in Lastoursville.

Maël Ntsinga is a PhD student in archeology, in Gabon, working with Richard Oslisly on surface prospections

Inventory of bat species in Gabon caves
Olivier Testa catches in a cave a Sundevall’s roundleaf bat, living among millions of flying insects