These boulder are pretty cool. I didn't know what they were when we were there and wished i knew so here...just for you...my short explanation from research i did when I got home. So you know what you'll be looking at ;)
They are a collection of about 50 round concretions scattered along Koekohe Beach. They are among the world's largest concretions at a whopping 7 tons and 8 feet in diameter. These lumps of sediment took 4 million years to grow and are bound together by a mineral cement. They started forming in a mud stone about 60 million years ago and were later lifted out of the sea and became part of the cliff line. Centuries of coastline erosion released them from the cliffs and they rolled down to the beach.
They are pretty cool to see and enjoy for a short while, would stop by if you're in the area or driving by.
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