Abismo Anhumas: Bonito's 72-Meter Cave Rappel

Abismo Anhumas sits 23 km from Bonito's town center, and the only way in is a 72-meter electric rappel through a narrow rock fissure. The cave floor holds a flooded chamber with an 80-meter-deep lake, visibility up to 60 meters, and limestone cones rising nearly 19 meters from the water — the tallest recorded cone of its kind in the world literature.

Every visitor enters on a guided tour, and daily capacity is capped at roughly 60 people split between morning and afternoon groups. That cap is why this is the first activity to sell out in Bonito, often weeks ahead in January, July and December.

What the Descent and the Lake Are Actually Like

The 72-meter drop

You descend in pairs on a steel-cable system driven by an electric motor, supervised by a technician. It takes about five minutes and requires no climbing skill or upper-body strength. The gap you pass through near the top is narrow — roughly 15 meters at its widest point — then the shaft opens into a hall guides compare to a stadium.

Height is the real filter here. If you freeze on exposed ladders or ledges, this is not the tour to test yourself on. There is no alternative stairway or exit.

Boat ride, snorkeling or diving

A floating deck waits at water level. From there, three formats exist: boat only (no water entry, about 3.5 hours total), boat plus snorkeling in 7 mm neoprene, or boat plus scuba. Certified divers stay in the upper basin to about 18–20 meters; a beginner "batismo" dive goes to 8 meters. Full technical dives reach 47 meters but sit outside standard tour packages.

The water holds steady at 17–18°C year-round while cave air stays near 20–21°C. The 7 mm suit with hood, gloves and booties is not a formality — I would not trade it for a thinner rental.

The light window

From November to February, the sun aligns with the cave opening and throws a direct beam onto the lake, which local guides call the divine light. October and February sit at the edges of that window. Outside it, the chamber is lit by artificial light and the mood shifts from spectacle to pure geology.

Booking, Training and Practical Rules

The mandatory check-in day before

You must appear at the Abismo Anhumas office in Bonito's center between 9 am and 6 pm the day before your descent. Staff explain safety procedures, you sign the risk form, try on the neoprene suit and receive your time slot. Skip this and the tour is cancelled — no refund. Late arrivals into Bonito the night before are the single most common planning mistake.

A training session on an 8-to-10-meter platform at the office is included for anyone doing snorkeling or diving. Expect to spend 40–60 minutes there.

Prices and what is excluded

Published 2026 rates run about R$ 997 for contemplation (boat only), R$ 1,598 for rappel plus snorkeling, and roughly R$ 1,857 for the scuba version. Children aged 5–12 pay around R$ 799 on the snorkel tour. Fees change with season and operator — check the official site for current rates.

Transport from Bonito is not included in most packages. Driving yourself takes about 30 minutes on paved road plus a short dirt stretch; taxis and pre-booked transfers are easy to arrange in town.

Age, weight and gear rules

Minimum age is 8 for the water activities, 5 for contemplation only. Maximum weight is 150 kg. Bring a normal T-shirt, long trousers (not jeans), sneakers, long socks and a swimsuit to wear underneath. Pack a towel and a warm layer. Sunscreen and insect repellent are banned inside the cave — they contaminate the water. Photography during the vertical descent is prohibited by the operator's own rules.

People with reduced mobility can be accommodated on the contemplation format, and the operation follows the NBR/ISO 21101 adventure-safety standard.

When to Go and How to Fit It Into Bonito

Season and weather

The cave itself barely reacts to surface weather — the lake level and clarity hold through the wet season. What changes is the road and your comfort. May to September brings little rain and cooler nights, which makes the early departure and the 18°C water easier to handle. January and July are peak crowds, so reserve three to four weeks ahead minimum.

If you are chasing the sunbeam, book November through February and accept afternoon showers. Build a backup date into your itinerary; heavy rain can close the access road briefly.

Pairing with nearby caves

Gruta do Lago Azul, 20 minutes away, is the natural half-day partner — its blue water and morning light work well the day before or after your abyss slot. Keep the abyss on a separate day from any long transfer. Doing it the morning after a late arrival from Campo Grande (a 3.5-hour drive) is the itinerary error I see most often.

Frequently Asked Questions

Do I need previous rappelling experience?

No. The descent uses a motorized system and you go down in pairs with a technician beside you, so fitness is not a factor. Fear of heights is the only real obstacle — the shaft is 72 meters with no alternate route out.

How far in advance should I book Abismo Anhumas?

Three to four weeks in high season (January, July, December); a week or more in low season. Capacity is capped near 60 visitors per day, and morning slots go first because they leave the afternoon free.

Can I visit without getting in the water?

The contemplation format includes the 72-meter descent and a boat tour across the lake but no water entry, and takes about 3.5 hours. It costs around R$ 997 and is the option for anyone travelling with children under 8 or wanting to stay dry.

What happens if it rains on my tour day?

Tours usually run — the cave is enclosed and the lake unaffected. The risk is the unpaved access road, which can become impassable after heavy rain; operators may reschedule you to another slot or date at no charge.