Geez, here I am on a poal Hawaii thread. The absolute, hands-down, coolest beach I have ever been to was a black sand beach on the big island. MacKenzie beach, 27 years ago. It doesn't even exist anymore because of a long, slow eruption from Mona Loa. I would love to tell the story, but I don't want to encourage you in flooding the site with local Hawaii news.(Someone scolded me that it's not spam, and they are technically right. It's flooding. Still annoying.)