Moeraki Boulders

The Moeraki Boulders are spherical stones on Koekohe Beach, a beach on New Zealand's South Island. In fact, the grey coloured spheres are not stones: they were created a long time ago by a cementation process that took place deep in the seabed. The age of the Moeraki Boulders, which have a diameter from 0.5 m to over 2 m, is estimated at about 5 million years. Other of these formations can be found on a coast further south in New Zealand and similar spheres can also be found on other continents, such as America.