The rocks of this headland are the remains of a molten trachyte plug which solidified under a volcano about 70 million years ago. Since that time erosion has worn away the softer overlay to expose the hard rocks of these plugs. Bluff Point, Pinnacle Point, Bluff Rock (Iron Pot Rock), Mount Wheeler and the mounts along Hedlow Creek were formed in the same way.

These columnar, hexagonal pipes are down towards the sea wall and Fisherman's Market, they were formed as the lava cooled and contracted.

The short track at Double Head not only offers panoramic views of Kemp Beach, Keppel Bay and the coast but also brings you to Fan Rock which is a fine example of "living" geology, you can see the core from which the trachyte 'pipes' have developed as the lava cooled.  This is an unusual geological formation as such 'cores' are normally hidden within the rock masses.