According to Tony O'Connell's Atlantipedia, the Richat Structure of Mauritania has been under review as a possible Atlantis site since 2006, when George Alexander and Natalis Rosen visited the site. Alexander & Rosen put together a 1-hour documentary about their findings, which is available on the Gaia channel for an introductory membership charge of 99 cents.
O'Connell (quoting Ulf Richter) says that "it is too wide (35 km), too elevated (400 metres) and too far from the sea (500 km) to be seriously considered as the location of Atlantis". Furthermore, Alexander & Rosen make no claims to have discovered any ruins of an urban settlement. See:
A YouTube video claiming that Atlantis is located in Mauritania received a big push over the past two weeks after Russian propaganda site Sputnik picked it up, along with the online British tabloids that follow Sputnik’s lead with clockwork regularity. ...
The video claims that that Richat Structure, or the Eye of the Sahara, is an eroded set of concentric rings in Mauritania about 40 km in diameter that geologists have concluded is a natural structure, probably a collapsed magma dome. This, of course, does not preclude it from being Atlantis, but a number of facts mitigate against it:
There is no evidence of human settlement anywhere on or around the structure. It was not a city.
The rings are not located anywhere near the sea, and it would take a powerful tsunami to flood two hundred miles from the coast.
As should be obvious, the Richat Structure is not underwater and therefore did not disappear beneath the waves never to be seen again. There is no evidence of it being underwater in the past 10,000 years.
It is not, as Plato said, opposite the Pillars of Hercules.
While the video claims that the diameter of the structure exactly matches Plato’s measurements for Atlantis of 127 stadia, this can only be matched by selectively choosing to ignore the outermost “ditch,” whose added measurements would outstrip Plato’s.
Obviously ... Jerry, the signs of human settlement were washed away in the massive tidal waves. The YouTube video acknowledges that the site is elevated, rather than submerged, so perhaps this may have been a satellite site to Atlantis? If such as Atlantis really sank, then other areas can rise.
There is a site just north of Cadiz, Spain with concentric rings that seems like it might be the same, also with geographic proximity to ancient metal mining.