It seems the sea level has been a lot lower during the prehistorian time and there, where today are the cliffs and the rocks of Capo Caccia, were land and meadows. It was full of little animals which have perished in a cave and there skeletons turned into fossils...
After thousands of years we can admire now their bones in the limestones of Punta Giglio.
In the wall of Punta Giglio, in ten meters depth, there is an entrance which leads to a siphon.
Dive trough this siphon and you reach a channel head which is aerated stadely with fresh air.
From there you can move into the next chamber, where the fossils are located.
Once again outward the cave, you can dive along the rock face or into another little tunnel and observe the spiny lobsters nursing themselves. Mostly there will be some Barracudas or other marine creatures to welcome you during the journey. A big grouper has been settling down there long ago and looks forward to your visit.