White-sand beaches aren't common. Pink-sand beaches are downright unusual. But only on the geological wonderland that is the Big Island of Hawaii can you find the rarest of them all -- a beach made of deep green crystals. Green sand beaches which are made from olivine crystals are rare. the only green sand beach on the Big Island is located at the southern most tip, Ka u.

Puu Mahana, Green Sand Beach, is located in the Kau' district. It is primarily located on the slopes of Mauna Loa, the world's largest and most massive active volcano on the southwestern part of the island. To get to this beach, one must either use a four wheel drive or hike six miles from South Point, Ka Lae, the southern most tip of the United States.

Nevertheless, each year the unusual green sands attract thousands of oglers, who follow a well-worn four-wheel-drive-only road for 2 1/2 miles to the top of a cliff, which you have to climb down to reach the beach. The sand is crushed olivine, a green semiprecious mineral found in eruptive rocks and meteorites. If the surf's up, check out the beach from the cliff's edge; if the water's calm, it's generally safe to swim.