The Moeraki boulders

Published: Aug. 30, 2011, 5 a.m.

In Māori tradition the remarkable spherical boulders on Moeraki beach are eel pots - or baskets of kūmara (sweet potato) washed ashore from the Ārai-te-uru voyaging canoe. To scientists the boulders are concretions, formed around 60 million years ago from sediment and calcite.