Blue Lake Cave
Mato Grosso do Sul
Blue Lake Cave, located in Bonito, Mato Grosso do Sul, Brazil, is a natural monument renowned for its spectacular subterranean lake over 50 meters long, illuminated by sunlight through a large circular entrance. The lake's waters turn an intense blue color seasonally from September to February, creating a mesmerizing spectacle. The cave features fragile calcareous formations and has yielded fossil remains of large Pleistocene mammals such as giant sloths, armadillos, and sabre-toothed tigers, attesting to its paleontological significance. Access to the cave is regulated to preserve its delicate ecosystem and geological features, with visitors required to be accompanied by authorized guides. The site also includes the nearby Nossa Senhora Aparecida Cave, notable for its speleothems resembling angelic figures, though it is closed to the public for safety reasons. Blue Lake Cave is a protected area since 1978, highlighting its environmental and scientific importance, and is one of the largest flooded caves worldwide. Its pristine beauty and ecological fragility make it a must-visit natural attraction in the region.
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Tip: Visit Blue Lake Cave between September and February to witness the lake's intense blue hues at their peak. Book your visit through authorized local guides in Bonito to ensure compliance with preservation regulations. Note that access to the cave is restricted to protect its fragile environment, and diving is only permitted for scientific research by professionals. Plan for a half-day trip and consider arranging transport from Bonito, located about 21 km away. Advance booking is recommended during peak tourist seasons to secure your spot.
Interesting facts
- •The lake inside Blue Lake Cave is over 50 meters long and illuminated naturally through a 40-meter diameter circular entrance.
- •Between September and February, the lake's waters turn an intense blue, inspiring the cave's name.
- •Fossils of large prehistoric mammals such as giant sloths, armadillos, and sabre-toothed tigers were found in the cave, dating back more than 12,000 years.
- •The cave is home to rare species like Potiicoara brasiliensis and Mega Gnidiella, emphasizing its ecological importance.
- •Diving in the lake is strictly limited to scientific research due to the cave's fragility and ecological sensitivity.
History
Blue Lake Cave and the adjacent Nossa Senhora Aparecida Caves were designated as natural monuments in 1978 by Brazil's National Institute of Historic and Artistic Heritage (IPHAN).
The protection status aims to preserve the fragile calcareous formations, the subterranean lake and its aquatic ecosystem, and the surrounding landscape.
Since then, visitor access has been regulated to prevent damage, with mandatory accompaniment by certified guides.
The caves have also been a significant paleontological site, with fossil discoveries dating back over 12,000 years to the Pleistocene epoch.
Place Guide
Main Hall and Subterranean Lake
The main chamber features a sloping floor leading down to a vast underground lake over 50 meters long. Sunlight filters through the large circular entrance, illuminating the lake and creating the cave's signature blue glow during certain months.
Nossa Senhora Aparecida Cave
This adjacent cave has no water and limited natural light. It contains large speleothems, some resembling angels with wings, giving the cave its nickname. It is closed to visitors for safety reasons.
Contact
Phone: (67) 99254-8990
