Fern Grotto Fern-Grotto Place Category: Attractions Profile Photos MapFern Grotto is a fern covered, lava rock grotto located on the Wailua River on the eastern side of Kauai in the Hawaiian archipelago. No Records FoundSorry, no records were found. Please adjust your search criteria and try again. Google Map Not LoadedSorry, unable to load Google Maps API. Driving Walking Bicycling Public Transport Miles Kilometers Previous Next Leave a Review Cancel replyYour email address will not be published. Required fields are marked *Review text Select a rating Name * Email * Website Save my name, email, and website in this browser for the next time I comment.