Fern Grotto
Though it's really not much to look at, visitors enjoy this longtime attraction, perhaps because of the serene boat ride up and down the Wailua River that allows you to see it. The grotto is a yawning lava tube swathed in lush fishtail ferns 3 miles up the river. Though it was significantly damaged after Hurricane Iniki in 1992 and again after heavy rains in 2006, the greenery has completely recovered. The Smith's Kauai tour group is the only legal way to see the grotto. You can access the entrance with a kayak, but if boats are there, you may not be allowed to land.
