The Forbidden Island reef flat is located in the Central East Coast (Kagman Peninsula) of Saipan, CNMI. The Forbidden Island reef flat is about 2,000 feet long and up to 230 feet wide. One swimming hole is located in the reef flat as well as a nearby grotto. This site is located within the Kagman Wildlife Conservation Area. Ok for ages 7 and up. Leave H2O in different spots on the way down so that you don't have to carry water back up, but know the stops where water is waiting.