A 40-kilometer circular geological formation in the Sahara Desert, visible from space and shaped by 100 million years of erosion. Ancient stone tools found nearby date back 2 million years.
In Mauritania’s Sahara Desert, the Richat Structure forms a 40-kilometer-wide circular pattern of sandstone, limestone, and igneous rock. Called the Eye of the Sahara, its rings became visible after 100 million years of erosion. Astronauts use its shape as a landmark from space, and scientists study its exposed rock layers to understand tectonic shifts. Stone tools left by early humans near the outer edges include hand axes dating back two million years. If you drive to the Adrar Plateau, you’ll see rock formations shaped by wind and ancient geological forces side by side.
The Richat Structure’s circular shape stretches 40 to 50 kilometers across, with raised ridges of quartzite and lower valleys of limestone. Erosion stripped away softer rock over time, leaving behind bands of red sandstone and white sedimentary deposits. The center contains breccias—broken rock fragments fused together—surrounded by dark gabbro and kimberlite from volcanic activity. Satellite photos reveal sharp lines where the structure meets the Erg Oudane dunes to the south. You can see how wind patterns have carved linear dunes that approach the formation’s edges.
Archaeologists have found over 200 Acheulean-era stone tools in dry riverbeds around the Richat Structure. These triangular hand axes and scrapers were used by Homo erectus groups between 1.2 million and 200,000 years ago. Excavations uncovered piles of stone flakes where tools were sharpened, indicating repeated visits to the area. Fossilized shells and plant material in the limestone layers prove water once existed here. Visiting these sites lets you stand where early humans processed food and materials under a very different climate.
You need a 4x4 vehicle and an experienced driver to reach the Richat Structure from Ouadane. The drive takes one hour across unmarked desert tracks with no signage. Once there, walk along the ridges to examine striped rock layers up close or take photos of the circular pattern from ground level. Drones can capture the full scale of the formation, but frequent sandstorms make flying difficult. Bring at least 4 liters of water per person, sun protection, and all food supplies—no shops or shelters exist within 50 kilometers.
The 15th-century town of Ouadane, 30 kilometers northeast of the Richat Structure, has crumbling sandstone houses and a mosque with original wooden beams. Its stone granaries stored gold and salt during trans-Saharan trade caravans. Closer to the formation, Fort Agouedir’s ruins include a watchtower and cistern built by Portuguese traders in the 1400s. Local families near the fort sell iron jewelry and leather goods made using traditional methods. Driving between these sites, you might pass camel herds led by nomadic herders moving between seasonal grazing areas.
Geologists confirmed the Richat Structure formed through tectonic uplift and erosion, disproving early meteorite impact theories. Its circular shape remains puzzling, though some suggest magma movements pushed rock layers upward unevenly. A fringe theory claims it matches Plato’s description of Atlantis, but no submerged ruins or advanced artifacts exist here. NASA astronauts first photographed it in 1965, and today satellite images help researchers track erosion rates. The site gained protected status in 2022 to preserve its value for geological studies.
Plan trips between November and February when daytime temperatures stay below 35°C. Book guided tours through agencies in Atar or Nouakchott that provide permits, drivers, and camping equipment. Permits from Mauritania’s Ministry of Culture are required to handle or remove artifacts. Guesthouses in Ouadane have shared bathrooms and limited electricity—bring a headlamp and sleeping bag. Mobile networks rarely work here, so rent a satellite phone for emergencies. Wear loose, long-sleeved clothing to respect local norms and avoid sun exposure.
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