Stromatolite

These red rocks are stromatolites - living rocks. They were discovered in
1954 (in our life time!). Stromatolites are layered limestone rock built by
single-celled cyanobacteria. These trap and bind sediments and some build
craggy towers and others build flat spongy mats. They are the oldest living fossils, the simplest form of life on earth three billion years ago, and were responsible for the production of oxygen.  I understand that these stromatolites are so important as they are the only known stromatolites in the world.

I have to say that we thought that they just looked like red rocks in the
water but obviously they are of importance to scientists. A couple of young
guys visiting from overseas asked us to explain to them what stromatolites
were but they were asking the wrong people. Like them, we only went looking
as we saw the sign post and even after visiting we weren't that much more
educated.  However, our neice Sandra has reminded us that she had previously told us about the stromatolites, but I am sorry I had forgotten.