I is for Island
These two are located in Crater Lake in Oregon.
Above is Wizard Island. It is the peak of a cinder cone volcano within the lake, and got its name from an early name for the lake, the Wizard's Cauldron. The island peaks about 750 feet above the average level of the lake.
Below is the Phantom Ship.The source of the name of this rock pillar formation becomes obvious in a fog.