The center Pacific Island group with many current and former US territories is Micronesia. This place is a subregion of Oceania that consists of thousands of small islands in the Western Pacific Ocean. Micronesia is composed of four main archipelagos called: Caroline Islands, Gilbert Islands, Mariana Islands, and Marshall Islands. It has tropical marine climate and is divided politically among several sovereign countries. Most of the islands are part of coral atolls which originated from coral reefs that grow on slopes of a central volcano.
