Akau Island (and the signs of coral dredging that created it)

From Wikipedia

Johnston Atoll is a 130 km² atoll in the North Pacific Ocean at 16°45′N 169°31′W, about 1400 kilometers (750 nm) west of Hawaii. There are four islands located on the coral reef platform, two natural islands, Johnston Island and Sand Island, which have been expanded by coral dredging, as well as North Island (Akau) and East Island (Hikina), artificial islands formed from coral dredging.