In this video the popular YouTuber BrightInsight claims that a geological structure known as Guelb Er Richat or the Richat Structure in Mauritania should strongly be considered the lost city of Atlantis.
To illustrate the claim, here is a picture of the Richat Structure compared to an artist's rendition of how Atlantis could have looked like based on Plato's descriptions:
There seem to be many coincidences / parallels between Plato's story and the Richat Structure, such as the size of the formation, mountains to the north, findings of elephant bones in Mauritania, a freshwater well in the center of the Structure, various archeological findings indicating possible human settlements, the grographical location, etc.
Here is what Wikipedia writes about the claim:
One location that has been proposed for the location of Atlantis is the Richat Structure. It lies near Ouadane, which was a Portuguese trading post and learning center established in 1487. The structure's dimensions are claimed to be similar to those described by Plato. This structure is generally considered to be a deeply eroded domal structure that overlies a still-buried alkaline igneous intrusion.
Here are a few newspaper articles about the story: