On the roadside between Maroua and Garoua, in the North Region of Cameroon, a marble field stretches across the semi-arid landscape. On its white, pink, and greenish slabs, some 500 geometric figures have been engraved by human hands -- perhaps three centuries ago, perhaps three millennia. The Bidzar site, first reported in 1933, remains one of the most enigmatic and least-known petroglyphPetroglyphAn engraving made on a rock surface by pecking, incising or abrading, as opposed to rock painting; a form of prehistoric art found on every continent.→ assemblages in Central AfricaAfricaThe cradle of humankind: the continent where the first hominins appeared, then Homo sapiens around 300,000 years ago, before the expansion to the rest of the world.→.

Mandara Mountains, North Cameroon region
The Mandara Mountains, a rocky massif bordering the North Cameroon region, near the Bidzar site. This landscape of rocks and savanna, characteristic of the Far North of Cameroon, has been continuously inhabited since Protohistory by populations speaking Chadic and Adamawa languages.

Bidzar (sometimes spelled Bitzar) is a village in the Mayo-Louti department, North Region, populated mainly by Guidar with a few Moundang and Guiziga families. West of the main road, an outcrop of cipolin-type calcite marble extends over several square kilometers. This marble -- traversed by chloritoschist veins that give it green, pink, or bluish tones -- had ideal characteristics for engraving: a relatively soft surface, sub-horizontal planes suited to incision. The engraved slabs concentrate near the junction with the road to Guider, over an area of 2.5 km north to south and 1 km east to west.[1]

Marble Geometries: Describing the Works

All the Bidzar engravings are geometric in character: tangent, concentric, and intersecting circles, hatched figures, linear networks. Among them are also cupules -- simple bowls ground into the rock, one of the most universal forms of rock art worldwide -- as well as motifs that some researchers interpret as schematic representations of objects or living beings.

Geometric petroglyphs, African rock art
Geometric petroglyphs in southern Africa (Richtersveld, South Africa). While rock art traditions vary across Africa, the Bidzar engravings share with other African sites a preference for abstract geometric motifs -- circles, lines, cupules -- whose exact meaning remains debated by specialists.

The technique used is indirect punctiform percussion: a punch is placed on the marble surface, then struck with a hammer, detaching a small flake. Repeated blows create the desired line. The craftspeople systematically chose the most uniform, least eroded surfaces, avoiding lapiezed or grooved areas. Nearly 500 representations have been counted across the site, distributed without apparent organization -- but with recurring themes suggesting shared intent.

A Dating That Defies Modern Methods

Dating the Bidzar engravings is one of the main scientific challenges. No radiometric dating has been possible: the marble contains no organic matter directly associated with the engravings, and OSL (luminescence) or rock varnish dating techniques remain difficult to apply to this type of support.

Kapsiki mountains landscape, Far North Cameroon
The Kapsiki Mountains in Far North Cameroon. These volcanic rock formations, close to the Bidzar region, have been inhabited since at least the first millennium AD by populations who took refuge in the highlands to escape Islamic conquests. The region's rock art fits into these complex historical trajectories.

The current estimate relies on chemical weathering of the limestone support: the more degraded the marble around the engravings, the older they are. This imprecise but possible reasoning yields a very broad bracket: 300 to 3,000 years. Some engravings may thus date from the early centuries AD, during the savanna kingdoms that preceded Islam in the region; others may be only a few centuries old. The layering of motifs -- some crossing or superimposing others -- clearly indicates multiple and successive occupations of the site.

A Unique Site in Central Africa

What makes Bidzar exceptional is the absence of any known equivalent in Cameroon. Unlike the great rock art traditions of North Africa (Tassili n'Ajjer, Ahaggar) or southern Africa (San, Drakensberg), where representations are often figurative -- animals, humans, hunting scenes -- Bidzar offers an exclusively geometric and abstract repertoire. This brings the site closer to the rock art traditions of the Ogooue (Gabon), also characterized by geometric figures, although the supports and themes differ.

Cupule and circle petroglyphs, South Africa
Cupule and circle petroglyphs in the Richtersveld (South Africa). Circular motifs and cupules constitute one of the most widespread graphic vocabularies in world rock art -- present in Africa, Europe, Asia, and the Americas. At Bidzar, they dominate the repertoire alongside linear networks specific to the site.

Alain Marliac, who conducted the first systematic excavations of the site in the 1970s-1980s, was the first to document the engravings rigorously and propose an interpretation. According to him, their recurrence and organization suggests they were linked to mythological or cosmogonic representations, perhaps to a proto-scriptural communication system or ritual practices of which the current Guidar populations have no memory. The meaning of these works was lost with the civilizations that produced them.

Threats and Conservation Prospects

The Bidzar site faces serious threats. The calcite marble that serves as support for the engravings is also the raw material for local cement factories and artisanal quarries. Decades of intensive exploitation have reduced the extent of the outcrops and irreversibly fragmented some slabs. Natural erosion compounds this degradation.

In 2018, Cameroon's Ministry of Arts and Culture submitted the site to the UNESCO World Heritage indicative list under criterion (i) -- a masterpiece of human creative genius -- thereby acknowledging the universal value of these engravings. This indicative inscription does not yet legally protect the site in a binding way, but constitutes a first step toward stronger legal protection.

Other sites in the region are also under prospection: the Tinguelin cliffs, Mount Makabai near Maroua, and several rocky formations in the Diamare region feature enigmatic designs whose origin and meaning remain to be elucidated. The prehistoryPrehistoryThe span of human history before the invention of writing, from the Palaeolithic to the Metal Ages, known mainly through material remains.→ of North Cameroon has doubtless not yet revealed all its secrets -- and it is near Bidzar, on a dusty roadside, that the first lines of this still largely unknown history can be read.