When you imagine the excitement early visitors to Diamond Head must have felt when they confused calcite deposits with real diamonds, it's easy to forgive their misnaming this extinct volcano. Today the state maintains a little monument, complete with a path leading up and through the mountain in former army bunkers. The trek is topped off with one of the best views of Honolulu from the summit. After filling up your camera's memory card head on back into the crater and consider enjoying some shave ice. There is a truck there that has got this cold snack down, just don't let the local population of pushy peacocks intimidate you into sharing.