Moeraki Boulders

The Moeraki Boulders are large spherical concretions littering the low-tide beach near Kaiki Point, between Oamaru and Dunedin. They began forming some 55 million years ago--lime has something to do with it--and are appearing now due to the general uplift of the islands and local erosion. They look like so many giant marbles scattered around on the beach, many more than meter in diameter, and they apparently elicit strange behaviors on the parts of some visitors.