The Mariana Islands were the hundred-odd islands in the archipelago. They'd gotten the name as they were situated close to the Mariana Trench, which was deep beyond comprehension.
It was rumored that there were once fishermen who stayed permanently on the islands many years ago. Slowly, as more and more people settled down there, they created an island country with a population of nearly a hundred thousand people. Unfortunately, its past glory was destroyed in the Land-Sea War that happened over five thousand years ago.