Kauai Hawaii Vacation Guide
The Fern Grotto is a popular tourist destination located on the Wailua River in East Kauai. It is a massive lava tube filled with ferns.
Located just north of Lihue, it can be accessed only by boat. Barges sail from the marina up the river for a distance of about two miles. A paved pathway then leads through some lush foliage into the cave.