Some are under the water. Some are under the sand. Some are in the banks. Some are nicely exposed. They are the Moeraki Boulders , on the East Coast of the South Island at Moeraki which is south of Oamaru.
If you read Meggie's Blog you will have seen photos of her with her children years ago sitting on the same rocks. Shirley lives quite near them.
They are granite and are I suppose harder than their surroundings hence there durability. We had to wait for most of the other folk visiting to drift away so we could get some shots of the rocks naked and in the raw. One shot shows a rock cracking and starting to disintergrate. That's me ( for a change I handed over the camera ) with the red shoe on a rock.