Honolulu is the capital of and the most populous census-designated place (CDP) in the U.S. state of Hawaii. Most of the city's commercial and industrial developments are located on a narrow but relatively flat coastal plain, while numerous ridges and valleys located inland of the coastal plain divide Honolulu's residential areas into distinct neighborhoods: some spread along valley floors (like Manoa in Manoa Valley) and others climb the interfluvial ridges. Within Honolulu proper can be found several volcanic cones: Punchbowl, Diamond Head, Koko Head (includes Hanauma Bay), Koko Crater, Salt Lake, and Aliamanu being the most conspicuous.