Fern Grotto

Fern Grotto - Kauai’s Royal Fern-Covered Cave
Local Expert's Rating:
4 / 5
The Bottom Line:

If you can appreciate the wonders and magic of nature all perfectly grown inside of a cave, then Fern Grotto is just the spot you want to visit. People have been coming here to gaze upon the flora, fauna, and acoustics for millennia, but it’s only recently that non-royalty were allowed to visit. Come, and see why this has been the birthplace of Hawaiian royals.

- The HawaiianIslands.com Local Expert Team

Fern Grotto is rich with geological and cultural history. People have been coming to see this fern-covered cave for millennia, but only recently have non-royalty been allowed to visit.

The cave at Fern Grotto was formed millions of years ago as lava eroded into the nearby stream. What makes this cave so remarkable today are the ferns that grow around and in it — many of them hang upside-down.

People have likely been coming to see this natural wonder since Kauai was first settled, but the feature was off-limits to all but the most royal until about 50 years ago. The location is believed to be the birthplace of Hawaiian Ali’i (royalty), and it’s certainly picturesque enough to be worthy of such an honor. Hawaiians opened the place up to visitors around 50 years ago.

The grotto itself isn’t the only thing to admire here, as the entire place is surrounded by Hawaiian beauty. Native flora mix with tropical plants to create a rich background against which the ferns sit, and a waterfall not too far away provides just enough mist to be comfortable. The grotto is even a natural amphitheater, and you might be lucky enough to hear someone playing classic Hawaiian songs.

Fern Grotto isn’t the most accessible place to visit, but it’s not too difficult to arrive at either. Almost everyone who comes arrives via a boat that traverses the river, and plenty of these boats are flat, stable, and easy to board and offboard.

Kauai is known for its ocean, lava, flora, and waterfalls. Few other places offer three of those four features in such a compact and beautiful setting. Make the trip upriver, and you’ll see why the royalty chose Fern Grotto.

A few of our favorite features at Fern Grotto include:

Grotto & Ferns
The grotto itself is the main attraction, covered in green ferns that hang down rather than grow up. The lush green plants cover the black lava soil, which provides a stark contrast when you photograph an individual fern up close.

Native & Tropical Flora
A combination of native and tropical plants provides a vibrant backdrop against which the Fern Grotto is set (and surrounded). See how many different plants you can see, and make sure to admire the collective rainbow of color too.

You’ll see larger waterfalls than the one nearby at Fern Grotto, but few are situated in a similarly beautiful setting. Enjoy the waterfall’s cooling mist as you admire the surroundings.

The presence of varied flora and accessible water attracts a wide variety of birds. Bring your binoculars for an up-close view, or just admire them from a distance. You’re still close enough to identify most without any aids other than a book.

Insider Tip:
Fern Grotto isn’t the only attraction along the river. Consider extending your trip upstream to Secret Falls and/or the King & Queen Bath — and bring a swimsuit for when the water is tempting.