One of the most popular tourism destinations in the Pacific Ocean, the Cook Islands are known for their immense natural beauty. While it has an association with New Zealand, which oversees its infrastructure and defence and grants the islanders citizenship, it is very much a self-governing country. Encompassing 15 separate islands, the biggest of which being Rarotonga, the Cook Islands are a unique destination in the Pacific, which offers some of the best quality diving in the world.