Two wet caves lie within the boundaries of Haʻena State Park. Formed by the constant pounding of waves many years ago, the massive cavern of Waikapalaʻe Wet Cave is as enchanting as it is spooky. It's on the opposite side and a short walk from the visitor-overflow parking area. Waikanaloa Wet Cave is further down on the south side of the highway.
Though some enter the water to experience the sunlight’s blue reflection in Waikapalaʻe's deeper chamber, note the water may be contaminated with leptospira bacteria; the rocks are slippery; and there's nothing to hold onto once you’re in the water. But it does make one hell of an Instagram glamour shot. Make sure you have someone watching out for you and shower immediately after.