What do astronauts, Atlantis and Africa share? The Richat Structure!

Nestled in Mauritania, surrounded by the towering and shifting dunes of the Sahara Desert, is the Richat structure. A spectacular rock formation with many names, the “Eye of the Sahara” has guided astronauts, inspired those seeking the lost city of Atlantis and baffled geologists. Yet, you could walk through this magnificent geological feature and never appreciate the concentric stone circles all around you. How did the Richat structure, something visible only from space, generate so much discussion, curiosity and admiration?

The Gemini astronauts of the 1960s saw the Richat structure for the first time!

The Richat Structure, or Guelb er Richat, lies a short distance from the town of Ouadane, which was once a hub of human learning in west-central Mauritania, on the western coast of Africa’s bulge.

Proof of the difficulty of observing the true scale of the formation from the ground, little was known about the Richat structure until man ventured into space. From Earth orbit, astronauts on the Gemini mission were the first to photograph what they dubbed “the eye of Africa” ​​in the 1960s, and it has since become a landmark for humans orbiting the Earth.

The structure of Richat: a dome and scattered stone rings

The Richat structure comprises a 198-meter (650-foot) dome composed primarily of breach; a type of rock made up of many smaller rocks fused together. Geologists classify this central plateau as a bulging anticline (rock folded in the shape of an arc, with the oldest rock in the center). Surrounding the plateau are concentric rings of stone with low valleys between each, forming a distinctly eye-like shape when viewed from above.

The structure is massive, measuring around 40 kilometers (25 miles) wide, and is composed of a variety of igneous and sedimentary rocks. While the composition and structure of the Richat are well documented, its origins are a source of ongoing debate.

Topographic map of the Richat work. (Valley / CC BY-SA 4.0 )

Is the structure of Richat the lost city of Atlantis?

Around 360 BC. BC, the Greek philosopher Plato wrote the “Dialogues of Plato”, in which he detailed a great city called Atlantis. Modern scholarship regards Atlantis as a myth, a rhetorical device, but this has not quelled enthusiastic speculation that the city was real, nor a dearth of people researching its location.

A YouTube video posted on the Bright Insight channel claims the Richat structure as the site of the lost city. Bright Insight host Jimmy presents a series of arguments for this, along with a handful of screenshots from a 2011 documentary called “Visiting Atlantis”, which posits the same theory. Jimmy’s arguments include:

  • Atlantis was destroyed 11,600 years ago, a time that corresponds to the Younger Dryas period, a period of glacial conditions that caused sea level fluctuations and devastating fires.
  • Plato describes Atlantis as having a central island surrounded by concentric rings of water and alternating structures; this description corresponds to the Richat structure.
  • Atlantis was supposed to be 127 stadiums, or 23 kilometers (14 miles) in diameter, which corresponds to part of the Richat. Jimmy notes that he used Google Earth to measure the distance, which may not be entirely accurate.
  • Atlantis lay in the shadow of the mountains to the north, through which rivers flowed in a wide valley, aligned with the structure of Richat.
  • There seems to be evidence of water leaking from the Richat structure into the ocean, suggesting that it was once surrounded by water, much like Atlantis.

While the video makes for an interesting 20-minute watch, many vehemently disagree with its theory and arguments. Their arguments are respectively:

  • The Younger Dryas occurred between 12,900 and 11,700 years ago, one hundred years outside the timeline of the destruction of Atlantis. Additionally, the period of glacial conditions lasted 1,200 years along the equatorial regions of the Earth (affecting North America more than anywhere else); Atlantis was said to have been destroyed in a single cataclysmic event over the course of a day.
  • The rings of the Richat structure are broken and incomplete, so it is unknown how many, if any, would have been filled with water. Moreover, there is no evidence of the channel crossing the rings cited by Plato.
  • Scientific measurement of the Richat structure puts it at around 40 kilometers (25 miles) wide, which means 17 kilometers (10.5 miles) must be ignored for Atlantis to fit.
  • There are mountains to the north, but that’s not a unique feature. Skeptics also wonder how closely the description of Atlantis surrounded by “flat plains” matches the Sahara desert.
  • The Sahara is 4.6 million years old and there is no evidence that it was covered with water only 12,000 years ago.
  • Moreover, skeptics wonder why no archaeological finds were made on the Richat structure if Atlantis was above it.

While the argument rages over whether the Richat Structure was once the site of an ancient civilization, scientists have grappled with an entirely different question: How did it form?

Satellite image of the Richat structure (false color).  (NASA/GSFC/MITI/ERSDAC/JAROS, and US/Japan ASTER Science Team / Public domain)

Satellite image of the Richat structure (false color). (NASA/GSFC/MITI/ERSDAC/JAROS, and US/Japan ASTER Science Team / Public domain )

The science of the eye of the Sahara

When first studied, scientists postulated that the “eye of the Sahara” was a astrobleme, the result of a meteoric impact. On closer inspection, however, it was discovered that none of the rocks showed signs of shocking processes.

Recent studies have discovered that the Richat is 100 million years old and was formed by volcanic activity. Deep underground, a massive cavern of magma formed and caused the surface of the Earth above it to swell. The boiling fluid then dissolved the surrounding limestone, causing the structure to weaken and collapse. On the surface, thousands of years of erosion have formed rings and valleys where channels of magma have formed or collapsed. The magma contained in the central dome hardened to form the massif of the breccia.

One question, however, continues to elude explanation: the Richat structure is isolated, whereas most volcanoes form in groups.

It doesn’t matter if you believe that Guelb er Richat was once the center of an ancient Atlantean civilization or not, the fact remains that it is a structure of extraordinary beauty. Astronauts have long been in awe of its majesty and use it to guide them as they float through the cosmos. Geologists have studied the riddle of the structure and racked their brains for decades over how it got there.

The structure of Richat, “the eye of the Sahara”, “the eye of Africa”, Guelb er Richat , whatever name you give it, is a massive eye-shaped rock formation that went unnoticed for millennia and continues to elude understanding today. There is a strange majesty in knowing that nature still holds mysteries for mankind to ponder.

Top image: a topographic reconstruction from satellite photos of the Richat structure with false coloration. False coloration as follows: Brown: bedrock; Yellow/white: sand; Green: vegetation; Blue: salty sediments. Source: NASA/JPL/NIMA/ Public domain

By Mark Johnson


Dietz, R., Fudali, R. and Cassidy, W. 1969. Domes of Richat and Semisyat (Mauritania): No astroblemes. GSA Bulletin flight. 80, no. seven.

Matton, G. and Jebrak, M. 2014. “The Eye of Africa” (Dôme de Richat, Mauritania): an isolated alkaline-hydrothermal complex from the Cretaceous. Journal of African Earth Sciences flight. 97.

Novella, S. 2018. No, Atlantis was not discovered in North Africa. Available at: https://theness.com/neurologicablog/index.php/no-atlantis-has-not-been-discover-in-north-africa/.

Richat structure. Earth Observatory. Available at: https://earthobservatory.nasa.gov/images/92071/richat-structure.

R.K. Eye on eye. Natural History flight. 114, no. 9 (2005).

Tapon, F. Entering the eye of the Sahara – The Richat structure. Forbes. Available at: https://www.forbes.com/sites/francistapon/2018/07/30/going-into-the-eye-of-the-sahara-the-richat-structure/?sh=3994a223cf5b.

The lost city of Atlantis – hidden in plain sight? Ancient lost human civilizations. Bright preview – YouTube. Available at: https://www.youtube.com/watch?v=oDoM4BmoDQM.