From Kona, drive about 70 miles south and then another 12 miles towards the ocean. This is a narrow and windy dirt road to the shore. Then, follow the crude signs to the Green Sand Beach path, which takes you across three miles of uneven pasture, beach rocks, and lava rock. Finally, you'll reach the top of the cliffs of the Green Sand Beach. Now, you'll have to navigate your way carefully down the cliff to the incredible dark sparkly green sands of this wonder of nature.
It's a terrible hike, especially since the wind blows against you all the way to the beach, but it's worth the effort. Take plenty of water and wear sunblock. Make sure NOT to wear flimsy sandals as you WILL get blisters.