The Northern Mariana Islands are a U.S. commonwealth in the Pacific Ocean. Saipan, the largest island, is known for its sandy shores and mountainous landscapes. In clear waters off its west coast is the tiny, coral-fringed Mañagaha islet. On Saipan's northeast coast, turtles inhabit the Grotto, a cavern dive site. Nearby, memorials mark Banzai Cliff and Suicide Cliff, sites from WWII's Battle of Saipan.