Um. The fact that (a) we have always built cities near shores and (b) shores cha

Um. The fact that (a) we have always built cities near shores and (b) shores change constantly, and (c) we are in what appears to be a glacial minimum, should provide a rather obvious explanation of why there are any number of underwater cities (architecture). Just like there are many buried cities. The earth ‘breathes’ like we do, on a fairly regular cycle.