The city of Honolulu, seen here from the rim of Diamond Head tuff cone, overlies the southern flank of the massive Koolau shield volcano, whose slopes rise to the right. Koolau shield volcano was constructed during the Pliocene to Pleistocene and has been extensively eroded. Diamond Head is part of the Honolulu Series, a group of tuff cones, cinder cones, and spatter cones constructed on the eastern flanks of Koolau following a long period of quiescence.

Photo by Lee Siebert, 1998 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Koolau