Mariana Islands
Archipelago in the north-western Pacific Ocean
Also just the Marianas, a crescent-shaped archipelago in the north-western Pacific formed by the summits of fifteen mostly dormant volcanic mountains lined up north to south, between 12° and 21° north and along 145° east. Lying east of the Philippines, north of New Guinea, west-southwest of Hawaii and south-southeast of Japan, they mark the eastern edge of the Philippine Sea.
Photo: CT Snow from Hsinchu, Taiwan, CC BY 2.0