text: The island is generally off-limits to all but relatives of the island 's owners , U.S. Navy personnel , government officials and invited guests , giving it the nickname `` The `` Forbidden Isle '' .
simplified: Niihau is also known as the `` Forbidden Island '' . This is due to the fact that until recently , the island was off-limits to all but family members , US Navy personnel , government officials and expressly invited guests .