Pūtangirua Pinnacles

[1][2] They consist of a large number of earth pillars or hoodoos[2] located at the head of a valley in the Aorangi Ranges, on the North Island of New Zealand, in the Wellington region.

Some 7 to 9 million years ago when sea levels were much higher, the Aorangi ranges were an island.

As this landmass was eroded over time, large alluvial fans formed on its southern shores.

[2] Since the ice ages, sea levels have receded, and the old alluvial fans have been exposed to the erosive forces of wind and water which have weathered away the conglomerate.

In some places this conglomerate is protected from erosion by a cap of cemented silt or rock; this has resulted in the formation of spectacular pinnacles, many of which have prominent fluting caused by rainwater running down their sides during major storms.