The location that fits Plato’s description no longer exists, y’know, because as he noted, it was lost to the sea “in a single dreadful day and single dreadful night”, never to be seen again. But I’d be pleasantly surprised if something major (like a submerged town) were found pretty much anywhere in the world. The former banks of the former estuaries would be the best places to start searching, IMHO.
Of course Plato just mentioned it in passing, so there was a lot of myth around it even then. Who knows, it may have originated with a Mycenean village of 200 being submerged by a wave in 1900 BC ;-P
Yup. The Rhine and Thames were once the same river.