Koko Head is the peninsula that overlooks and creates the southwest side of Hanauma Bay
. There are two craters on Koko Head, as well as telecommunications facilities. It is reached by Kalanianaole Hwy (Hwy 72), which becomes H-1 in Honolulu
The Nature Conservancy maintains a preserve in the larger crater and conducts hikes and excursions on weekends to the preserve. Call for information.