🌌 Acaiá Cave: The Fluorescent Adventure in Ilha Grande
- Marcelo Alvim Marvim Click
- Aug 20, 2025
- 2 min read
Updated: Nov 11, 2025
Discover Gruta do Acaiá, a fluorescent cenote hidden in Ilha Grande: perfect for those seeking adventure, unique photos and rarely seen nature.
🔗 Navigation Menu
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1. What is the Acaiá Cave?
The Acaiá Cave is an incredible coastal cenote with fluorescent green and blue water. Sunlight streams through a crack in the rocky ceiling, magically illuminating the water—a rare natural phenomenon, the only one of its kind in the Americas.
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2. How does the tour work?
You can get there in two ways:
By boat/speedboat/schooner, on routes that combine Gruta do Acaiá with Lagoa Verde and Lagoa Azul.
By trail, starting from Praia Vermelha via T7/T8 (approximately 5 km round trip), crossing Araçatibinha and sparse vegetation.
The visit includes crossing the narrow part of the cave — about 10 m crawling — and disembarking on an “underground beach” inside the cavity.
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3. What's included
✅ Included:
Transportation by speedboat with certified guide/sailor
Stops at Lagoa Verde and Lagoa Azul
Illuminated entrance to the cave (not covered by fee)
Vests, water, coolers (varies by operator)
❌ Not included:
Cave access fee (average R$25–50 per person)
Lunch, drinks or transfers until boarding
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4. Highlights and curiosities
Fluorescent phenomenon: Sunlight creates turquoise-green haze with bright “diamond”-like spots.
Impressive dimensions: ~30 m wide, ~1 m high, ~8 m deep.
Unique geological formation: an underwater rock pool with a ceiling resembling a large bottle.
Archaeological site: human remains between 250 and 3,000 years old, shell middens and local stories.
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5. Price, fees and reservations
Item Approximate Value
Speedboat ride R$ 200 – R$ 250 pp
Cave entrance fee R$25 – R$50 (payable on the spot)
Duration 7–8 hours, departure around 10:30 am, return around 5:30 pm
🎯 Book 7 to 60 days in advance, especially during peak season.
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6. Reasons to book now
Rare phenomenon: only visible on sunny days, in the morning (8am–11am) and at low tide.
Controlled capacity: the cave only receives visitors in small groups.
Exclusive tour: you visit three unique attractions in one day.
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7. Tips to make the most of it
Bring a headlamp (do not use a flash, to avoid erasing the fluorescent effect).
Wear clothes that can get wet or dirty, and sturdy footwear (crawling and slipping are possible).
Not recommended for claustrophobics or those afraid of low places.
Use sunscreen, insect repellent, bring a snorkel and water.
Ideally, arrive early at the pier (30 minutes before) and check the weather forecast.
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8. Conclusion + Call to Action
Visiting Gruta do Acaiá is like immersing yourself in a magical world—an experience few know, but everyone loves. A safe and surprising adventure with unique scenery on Ilha Grande.
📣 Want to secure this incredible experience? Get in touch and book now:
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