A Hike to Ka'au Crater Ka'au Crater by Dayle Turner Of the craters on the island of Oahu, the most familiar to residents and visitors are Diamond Head and Koko Head. Fewer know about Ka'au, a small crater tucked against the spine of the Koolaus. According to Hawaiian legend, Ka'au was formed as a result of an unsuccessful island-unification effort by the demigod Maui. While attempting to consolidate Oahu and Kauai into a single land mass, Maui saw his efforts end when the magic fishing line he had been using suddenly snapped. The huge hook affixed to his line sailed skyward, landing in upper Palolo and forming Ka'au Crater.
Geologists tell a different story.
In the scientific version of the genesis of Ka'au, the crater was formed from an explosive upswelling of volcanic material from deep within the earth's core. In geological terms, Ka'au is classified as a tuff cone, its foundation composed primarily of porous rock formed by compacted volcanic ash and dust. The trail to Ka'au begins in a quiet neighborhood at the end of Wai'oma'o Street on the Maunalani Heights-side of upper Palolo Valley. Affixing our John Hancocks to the latter was necessary because we'd be entering kapu watershed land. After a quick roll call, we shoved off at a few minutes before nine.