Fern Grotto, Kauai
- Name: Fern Grotto
- Where: Up the Wailua River on the East Side
- What: Natural, fern-filled grotto on the Wailua River
On Kauai’s East Side, the Fern Grotto is one of Kauai's signature attractions. Accessible only by a short boat trip up the Wailua River, the grotto is a natural lava-rock grotto, lush with hanging ferns and tropical foliage, cooled by the mists of a waterfall. There was a time when the Grotto was off-limits to all but Hawaiian royalty. But for more than 50 years, riverboats have provided tours of the site.