It is said that Captain Cook, the first Englishman to discover the Hawaiian Islands, saw blue light coming out of the whole hill at night, shining like sapphire. He thought he had found a diamond, so he called it Diamond Hill, while the local Chinese thought it was like a Wolong. From Wikipedia to Diamond Hill, driving or taking a bus is very convenient. Walking trails are slightly challenging, requiring two groups of 175 steps, sometimes flashlights through dark tunnels or old military bunkers.