This looks like a bunch of cement slabs emerging from the sea.
But actually they are sheets of fossilized shells. They are about 40 million years old and appear only in a few places in the world. Susaan means cemetary, and hoi means shell or mollusc.
Other than acknowleding their existance by taking pictures, I know too little about this to write authoritatively. So I'm afraid you'll have to crawl away and research this on your own. :)
http://michal.guerquin.com/photo/thailand/november2005/susaanhoi.html, updated 2006-04-05 00:55 EDT