Stromatolites are cyanobacterial reefs - one of the oldest forms of visible life on our planet. Fossil stromatolites, like the ones shown here on the To Ndu beach and high up on the cliffs, have been carbon dated in other parts of the world dating back 3.5 billion years.

The cyanobacteria cement particles of sediment together in concentric layers forming mushroom or egg-shaped "colonies". The colonies are not especially large. The one Freddy is sitting on (to give you a sense of the size of the colonies) is about a metre in diameter. But the ancient stromatolite colonies clustered together to form massive reef structures.

The island of To Ndu, some 15 miles west of Noumea, is actually a fossil stromatolite reef, 1.3km long by 0.4km wide and 70 metres above the sea floor making it one of the larger fossil stromatolite reefs in the world. On the eastern side the sea has erroded the stromatolites, forming a flat surface tiled with the cross sectional view of the ancient colonies.

The concentric fossil colonies you see in this sphere image are undoubtedly very, very old but this ancient form of life is still alive and thriving here in New Caledonia (reference Pringault & Camoin 2005).