Mahabalipuram is the tip of the iceberg. I grew up in different parts of India, ususally in coastal towns, and having always had a fascination with the sea, the local fishermen were my best friends.
I have always been amazed at how accurate local mythology is regarding submerged structures. In ancient cultures (those that have not seen huge migrations of peoples) the fishermen (or locals) can trace back how many generations ago these structures were seen. These folks are often illiterate and cannot count, but they know how to add 1 to their number, because they count their fish by ones (add 1 to the previous number).
Thus, I think structures will be found around many coastal towns around the world, if we listen, and... count.