Fodor's Expert Review Fern Grotto

Though it's really not much to look at, visitors seem to like this longtime attraction, perhaps because of the serenity of just cruising up and down the Wailua River, accompanied by Hawaiian music, to see it. The grotto itself is nothing more than 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 way to legally see the grotto. You can access the entrance with a kayak, but if boats are there, you may not be allowed to land.