Ahupuaʻa O Kahana State Park on Oʻahu’s windward side is Hawaii’s only public ahupuaʻa, preserving a traditional land division that stretches from Kahana Bay to the 2,670-foot summit of Puʻu Pauao. Its exceptionally wet valley supports varied habitats, from coastal pasture and fishponds to inland rainforest with native fish and birds. Before Western contact, Kahana sustained a strong Hawaiian community through fresh water, seafood, and irrigated taro, but that community declined sharply in the early 1800s amid disease, sugar cultivation, and later military training during World War II. The park now protects both natural resources and a lived-in cultural landscape.