Just over the hill from Makatu in the Bay of Plenty is Little Waihi. It's well worth taking a look. When I was a kid this was THE place to get pipis' by the sack full in just a few minutes. We went there regularly with our parents who loved all seafood.
Take a walk out to the ocean along the boulder and rock beach at low tide. You can see the cliff eroding and releasing (probabaly re-releasing) rocks from the clay cliff face.