Mount Susu

 mountain, panoramic view

Mt. Susu is an ancient volcano, one of two volcanos that formed the island. To look at it today it's hard to tell that was a volcano. The mounds in the photo are the rim. The left side is where the spill way was. The right side of the photo is looking towards Mt. Topochau.
This area is one of the few places on Saipan where volcanic rock is found. Rare metemorphic stones such as quartzite are found here as well.
Most of Saipan is limestone. The limestone comes from ancient coral reefs. The volcanic action that formed the island pushed this coral reef to the surface along with the magma. Thousands of years of time eventually changed the calcite skeletal remains of tiny marine organisms into the limestone rock that you see today.