The following morning we were off again heading for Hamelin Pool, home of the living rocks, known as the Stromatolites. It is one of only 2 places in the world where living marine stromatolites exist. They are known as the oldest and largest living fossils ever found. Stromatolites are colonies of micro organisms that pull oxygen from the water around them and oxygenate the surrounding area, blowing bubbles continually. They were able to grow here because of the extreme salinity of the water and the occurrence of calcium bicarbonate, as well as the limited circulation of the water. Apart from their unique nature, they were also very beautiful to look at, the crystal blue waters of Hamelin Pool providing a clear looking glass through which to see these fascinating grey-black lumps.