Kure Atoll is a coral atoll and also the oldest island of the Hawaiian chain. It’s believed that the island was formed over 30 million years ago and is also the most remote atoll in the world. Of the major islands, Kauai is known to be the oldest of the eight and was formed approximately 5-5.5 million years ago. This volcano has been extinct for millions of years. The youngest Hawaiian island is the Big Island, and is believed to continue to grow for millions of years to come.