Panalu\'u is the famous black sand beach on the main and largest island of Hawaii. The sand is formed of basalt and created from lava flowing into the ocean, and exploding as it hits the water to cool. This is a beautiful location to view some endangered species, like the beautiful green sea turtle. The water is an interesting mix of hot and cold water, because the sea water mixes with fresh water that bubbles up from underground. Though the beach is rocky and at times can be dangerous to swim, it is a beautiful location for dipping your toes and sunbathing.