In short
- Fern Grotto requires a 90-minute guided boat tour and a short, paved walk.
- Secret Falls requires a two-mile kayak paddle and a muddy 1-2 hour hike.
- Independent kayakers cannot access the Fern Grotto landing.
In this article
Choosing between the Fern Grotto and Secret Falls depends on your physical mobility and how much time you have. Both are located on the Wailua River, but they cater to entirely different types of visitors. The grotto provides history and music, while the waterfall trail requires physical effort.
What is the Fern Grotto experience like?
The Fern Grotto is a relaxed, 90-minute round-trip guided boat tour.
You ride a spacious, open-air riverboat for two miles upstream. The crew provides live Hawaiian music and hula dancing. Once docked, you take a flat, 10-minute paved walk through the rainforest to a wooden observation deck. Since 2006, you cannot walk inside the cave due to rockfalls. Instead, musicians perform the Hawaiian Wedding Song from the viewing platform.
What is the Secret Falls experience like?
Secret Falls is an active half-day adventure involving kayaking and hiking.
You must paddle two miles up the Wailua River to a muddy pull-off area. From there, you face a 1-2 hour hike to Uluwehi (Secret) Falls. The trail requires stream crossings and gets very slippery. You need water shoes with good grip. Guided tours take about six hours and provide safety gear.
How do costs and time compare?
The Fern Grotto is shorter and costs less than kayaking to Secret Falls.
Adult tickets for the Smith's Fern Grotto River Cruise cost $35. Kayak rentals for Secret Falls cost $75 to $105, and guided kayak tours start around $95. The boat cruise takes 90 minutes. A trip to Secret Falls requires at least four to six hours.
| Feature | Fern Grotto | Secret Falls |
|---|---|---|
| Transport | Guided riverboat | Kayak & hike |
| Time Needed | 90 minutes | 4 to 6 hours |
| Cost (Adult) | $35 cruise ticket | $75+ rental or $95+ guided |
| Physical Effort | Low (paved path) | High (paddling & muddy hike) |
Can you visit both in one trip?
You cannot visit both on the same tour or rental.
Independent kayakers paddle the river, but they are strictly prohibited from landing at the Fern Grotto. If you rent a kayak to hike to Secret Falls, you cannot stop at the grotto. To see both, you must book a kayak trip for Secret Falls and buy a separate riverboat ticket for the Fern Grotto.
Which is better for families with young children or seniors?
The Fern Grotto is the best option for visitors with limited mobility.
The Smith's boat tour requires stepping onto the boat, but the path to the grotto is paved and flat. Children aged 2 to 12 ride for $17.50. The Secret Falls hike involves slippery mud and walking through water. This terrain is dangerous for seniors or young children.
Do I have to pay state park fees for both?
Non-Hawaii residents must pay state park fees regardless of which option they choose.
As of February 2026, Wailua River State Park requires a $5 entrance fee per person and a $10 parking fee per vehicle. You pay these fees via credit card. Some guided kayak tours include these parking fees in their pricing.
Questions travellers ask
Are there alligators in the Wailua River?
No. There are no alligators in the Wailua River or anywhere in Hawaii.
Can I kayak to the Fern Grotto?
Independent kayakers can paddle the Wailua River, but they are strictly prohibited from accessing the Fern Grotto landing directly.
What should I wear?
For the Fern Grotto, wear comfortable walking shoes and a light rain jacket. For Secret Falls, you need water shoes with good grip and a dry bag for your belongings.
