Johnston Atoll Geography - note

strategic location in the North Pacific Ocean; Johnston Island and Sand Island are natural islands, which have been expanded by coral dredging; North Island (Akau) and East Island (Hikina) are manmade islands formed from coral dredging; the egg-shaped reef is 34 km in circumference; closed to the public; a former US nuclear weapons test site; site of now-closed Johnston Atoll Chemical Agent Disposal System (JACADS); most facilities dismantled and cleanup complete in 2004; some low-growing vegetation