The first time you see them, it’s hard to believe your eyes. Against the black, jagged lava of the Big Island’s Kohala Coast, shallow pools shimmer with a metallic gold tint, as if someone spilled liquid metal across the shoreline. These are the anchialine pools at Keawaiki Bay, and they’re one of the most unusual natural sights in Hawaii. The golden color comes from a unique algae that produces carotenoid pigments, creating a reflective sheen that’s strongest when the sun hits at the right angle. Getting there requires a short but sharp 0.7-mile hike across ʻaʻā lava from the 1859 Mauna Loa eruption, which naturally limits daily visitors to around 30–50 people. This guide covers the two best spots on the Big Island for experiencing these volcanic shoreline pools — Keawaiki Bay and Kīholo Bay — and what you need to know to visit them responsibly.
Anchialine pools are rare brackish water ecosystems found only in a few places worldwide, and Hawaii’s Big Island has some of the most accessible examples.
These pools are worth the effort if you’re after something genuinely different from Hawaii’s typical beach day. The trade-off is real: no swimming in the golden pools at Keawaiki, and the lava trail will test your footwear. Kīholo Bay lets you swim, but the 1-mile hike and lack of facilities mean it’s not a casual stop. Both reward patience and preparation.
Photographers
Nature lovers
Solo travelers
Below is a quick comparison of the two main spots covered in this article, so you can decide which fits your day.
| Spot | Best For | Standout Feature | Time Needed | Key Tip |
|---|---|---|---|---|
| Keawaiki Bay Golden Pools | Unique photography, solitude | Golden algae pools, ancient petroglyphs | 1.5–2 hours | Arrive before 9 AM for the best light and fewest people; parking fits only 6–8 cars. |
| Kīholo Bay Anchialine Pools | Swimming, turtle encounters | Thermal layers (warm surface, cool spring water below) | 2–3 hours | Morning hours from 7–10 AM offer the highest turtle activity and coolest hiking temps. |
Keawaiki Bay Golden Pools: Liquid Metal on the Kohala Coast
Keawaiki Bay sits about 20 minutes south of Kona International Airport, just off Highway 19 near mile marker 78.5. The trailhead is easy to miss — look for a small pullout that accommodates 6–8 vehicles. The 0.7-mile path crosses sharp ʻaʻā lava from the 1859 Mauna Loa eruption, gaining only about 25 feet of elevation. Sturdy closed-toe shoes are non-negotiable; running shoes can disintegrate within 15 minutes on the razor-sharp rock. The trail follows part of the ancient King’s Highway, a hand-built path that once connected coastal communities, and you’ll pass petroglyphs with 15–20 identifiable human figures and canoe designs along the way.
Park at the pullout near mile marker 78.5 on Highway 19. Put on sturdy hiking boots or trail shoes with thick soles. Bring at least 1 liter of water per person — the lava field has zero shade. Apply reef-safe sunscreen before you start; the black rock reflects heat and intensifies sun exposure.
Follow the worn path across the ʻaʻā lava field. The walk takes about 20–25 minutes one way. Watch your footing on the loose, jagged rock. Morning hikers often spot native Hawaiian birds like the ʻElepaio flycatcher in the naupaka shrubs. The trail is unmarked in places, so keep the ocean on your left as a reference.
The pools range from 3–10 feet in diameter and 1–3 feet deep. Water temperature stays consistent at 78–80°F year-round. Swimming is strictly prohibited to protect the unique golden algae ecosystem. The best light for photography is early morning, when the sun hits the water at a low angle and the metallic shimmer is strongest.
Walk south toward Pueo Bay for clear snorkeling water and regular green sea turtle sightings — turtles appear during roughly 85% of visits between 10 AM and 2 PM. Look for the ruins of a traditional heiau temple partially buried by the 1859 lava flow. The lone coconut palm near the pools is estimated at 60–80 years old.
Lava rock surfaces reach 95–105°F under the midday sun, even in November. Visit before 9 AM or after 3 PM to avoid the worst heat and get the best light for the golden pools.
Kīholo Bay: Swim Through Warm and Cold Layers
About 10 miles north of Keawaiki, near mile marker 82 on Highway 19, Kīholo Bay offers a different kind of anchialine pool experience — one where you can actually swim. The 1-mile coastal hike across lava rock takes 25–30 minutes at a steady pace, and the reward is a series of turquoise-blue pools where warm ocean water meets cool freshwater springs. The temperature shift is dramatic: surface water sits around 77°F in December, while diving just two feet deeper hits a cool 72°F from underground springs that traveled from Mauna Loa over thousands of years.
Park along Highway 19 near mile marker 82. Look for an unsigned dirt road leading toward the ocean. The 1-mile walk across rough lava rock takes 25–30 minutes. Closed-toe shoes with thick soles are essential. Morning hours offer the coolest temperatures and calmest conditions; afternoon trade winds kick up dust and increase heat reflection off the black rock.
Swimming is allowed in shallow areas under 6 feet deep. The thermal layers create strong currents where freshwater meets saltwater, so avoid the deepest central areas where underwater caves can create unpredictable flows. Never swim alone. The golden tint in some pools comes from iron and sulfur deposits, strongest during low tide when freshwater concentration peaks.
Green sea turtles choose these pools for the temperature variation, which creates different algae zones for complete nutrition. Recent visitor logs report an 85% success rate for turtle encounters, with peak hours from 8–11 AM. Federal law requires you maintain 10 feet of distance. Expect to see 2–8 turtles per visit.
King Kamehameha I ordered construction of the Wainanali’i fishpond here in 1820. The 1859 Mauna Loa eruption destroyed the original walls, but stone remnants still emerge at low tide. These remnants are a tangible link to the traditional Hawaiian aquaculture that once sustained the coastal village here.
Strong currents form where freshwater springs meet saltwater in the deeper pools. Stay in shallow areas under 6 feet deep and never swim alone. Underwater caves in the central zone create unpredictable flows that can pull swimmers unexpectedly.
Practical Section: Getting to the Pools, What to Bring, and When to Go
Both Keawaiki Bay and Kīholo Bay require a hike across sharp lava rock with no facilities at the end. Preparation makes the difference between a memorable morning and a miserable one. Below is a direct comparison of the two hikes.
| Factor | Keawaiki Bay | Kīholo Bay |
|---|---|---|
| Hike distance (one way) | 0.7 miles | 1 mile |
| Elevation gain | ~25 feet | Minimal |
| Swimming allowed | No | Yes (shallow areas only) |
| Parking | 6–8 vehicles at mile marker 78.5 | Roadside near mile marker 82 |
| Best time | Before 9 AM | 7–10 AM |
| Daily visitors | 30–50 | Under 100 |
What to Bring
Sturdy closed-toe shoes are the single most important item. Running shoes or sandals will not survive the lava. Bring at least 1 liter of water per person — there is no shade on either trail, and the black rock radiates heat. Reef-safe sunscreen, a hat, and polarized sunglasses help with the glare. For Kīholo Bay, pack a snorkel mask if you want to see the thermal layers up close. A small dry bag is useful for keeping valuables safe while swimming.
Seasonal Timing and Weather
December temperatures on the Kohala Coast range from 68–82°F, making winter the most comfortable season for these hikes. Summer months bring higher heat and stronger afternoon trade winds. Morning hours are consistently the best window — cooler temperatures, calmer conditions, and the best light for photography. Afternoon winds kick up dust and increase heat reflection off the black rock, making the hike back less pleasant.
Safety and Etiquette
Never swim alone at Kīholo Bay due to unpredictable currents in deeper areas. At Keawaiki Bay, the golden algae ecosystem is fragile — the “Gold Not for Touching” education campaign launched in 2024 to remind visitors not to enter the pools. Community volunteers patrol on weekends to prevent damage. Green sea turtles are protected by federal law; maintain 10 feet of distance at all times. No facilities exist at either location, so plan bathroom breaks before you arrive.
Parking at Keawaiki Bay fits only 6–8 vehicles. If the lot is full when you arrive, do not block the highway or park on the shoulder — move on to another spot and try again earlier the next day.
- Choose Keawaiki Bay for photography and solitude; choose Kīholo Bay if you want to swim and see turtles.
- Both require sturdy shoes, water, and an early start — no facilities, no shade, no shortcuts.
- Swimming is prohibited at Keawaiki to protect the golden algae; swimming is allowed at Kīholo but only in shallow areas.
Before You Go: Big Island Anchialine Pool Questions Answered
Can you swim in the golden pools at Keawaiki Bay?
No. Swimming is strictly prohibited to protect the unique golden algae ecosystem. The brackish water contains species that evolved in isolation over thousands of years, and human contact can damage the algae that creates the metallic shimmer.
If you want to swim, head to Kīholo Bay instead, where swimming is allowed in shallow areas under 6 feet deep. The thermal layers there offer a completely different experience — warm on the surface, cool just a few feet down.
Are these pools safe for kids?
It depends on the kids. The lava trails are sharp and uneven — not suitable for children under 8 or anyone unsteady on their feet. Kīholo Bay is the better option if you want to swim, but the currents in deeper areas mean you need to keep kids in shallow water at all times.
Keawaiki Bay’s shorter trail is manageable for older kids who are used to hiking, but the lack of swimming and the intense heat on the lava field can make it a tough sell for younger children.
Which spot has better turtle sightings?
Both offer excellent turtle viewing, but Kīholo Bay edges ahead with an 85% success rate reported in recent visitor logs. Turtles are most active between 8–11 AM. At Keawaiki Bay, Pueo Bay just south of the main pools offers reliable sightings between 10 AM and 2 PM.
Federal law requires you to maintain 10 feet of distance from green sea turtles at all times. Do not touch, chase, or block them.
Is the golden color guaranteed?
No. The golden shimmer depends on sunlight angle, time of day, and water conditions. It’s strongest during low tide when freshwater concentration peaks, and during golden hour lighting in early morning or late afternoon. Overcast days or midday sun can make the pools look like ordinary brackish water.
If you’re visiting specifically for the golden effect, plan for a morning arrival and be prepared to wait for the light to shift. The pools are still worth seeing even without the metallic sheen — the contrast of turquoise water against black lava is striking on its own.
Are these spots worth the hike if I’m short on time?
Only if you genuinely value solitude and unique geology over convenience. Both spots require a 20–30 minute hike across sharp lava with no facilities at the end. If you have a single day on the Kohala Coast and want a guaranteed payoff, Hapuna Beach or Punaluʻu Black Sand Beach are easier and more predictable.
That said, Hapuna Beach sees over 2,000 daily visitors during peak season, while Keawaiki averages 30–50. The effort filters out crowds, and that’s the whole point.
Why These Pools Reward the People Who Show Up Prepared
Anchialine pools are rare worldwide, and the Big Island has two of the most accessible examples — but “accessible” here means a short hike across volcanic rock, not a parking-lot-to-pool walk. The effort is the point. It filters out the casual crowd and leaves you with a shoreline that feels genuinely remote, where the only sounds are waves and native birds. Whether you’re photographing the golden shimmer at Keawaiki or floating through thermal layers at Kīholo, these pools offer something most Hawaii beach days don’t: a sense that you found it yourself. If you’re planning a trip that includes more of the island’s volcanic landscapes, the guide to Big Island Volcanoes National Park covers another side of the same geological story.
References
Journée Mondiale. “Golden Algae Pools Shimmer Against Black Lava Where Hawaii Hides Liquid Metal.” Journée Mondiale, 2025. ↗
Journée Mondiale. “This Big Island Bay Shifts From Warm Ocean to Cold Springs as You Swim.” Journée Mondiale, 2025. ↗
If you’re still building your Big Island itinerary, the guide to Hawaii’s best sunrise spots pairs naturally with an early morning at these pools, since both reward the pre-dawn crowd. For families weighing similar off-the-beaten-path stops, Oahu’s secret beaches guide covers a comparable mix of access difficulty and payoff.
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