O‘ahu is 44 miles (71 km) long and 30 miles (48 km) across. Its shoreline is 227 miles (365 km) long. The island is composed of two separate shield volcanoes: the Wai‘anae and Ko‘olau Ranges, with a broad "valley" or saddle (the central O‘ahu Plain) between them. The highest point is Ka‘ala in the Wai‘anae Range, rising to 4,003 feet (1,220 m).
Picture : Drone