This is a State Park that was once a royal fish pond (lava-block walls were built to protect the bay in 1820). A lava flow a few decades later wrecked it. Now it's the best place to see sea turtles on the Big Island. We came here for that reason since we were surprised by the lack of turtles elsewhere on the island (compared to Maui, where sometimes it's hard to see the fish because there are so many sea turtles in the way). There is an easy trail across the lava fields from the highway that takes about 20 minutes or so to reach the bay.
This was a very interesting and scenic beach on the surface, but underwater, visibility was terrible. There wasn't any coral that I could see in the murk. We swam a bit out of the bay to see if it would clear up, but it was the same out there. I assume the milky visibility is from all the fresh water flowing into the bay from the nearby pond.
