Good, and close, but the richat structure is a subsided volcano…it is not unique except that it has been very well preserved due to very low erosion environment. I would suggest you look for a similar geographic structure, but about a mile-3 kms underwater (due to plate subsidence + 400 foot sea level rise) on the volcanic plateau that the azores are the very tippy top mountain peaks of. Lines up perfectly with the historical references as well as the removal of several miles of ice depressing the north american plate (and thus pushing up its edges ar the seam which is the mid-atlantic ridge)
If you really want to find the civilization the Atlantis myths were referring to, look there. And I do think there is some evidence that is the origin source of the secret knowledge societies. The few Atlantean survivors embedded themselves as the upper class among other peoples, like the Aztec Quetzaquotl myth.