This pool lies undisturbed, a testament to carbon dioxide’s incredible stability and density. The gas is so heavy and stable that even small animals like insects and frogs that haplessly fall into it die instantly without disturbing its ghastly camouflage.
The dangers become clear when visitors lower a small burning log into the pool. As soon as the flame touches the carbon dioxide, it gutters out, deprived of the oxygen it needs. The log is extinguished so abruptly that it demonstrates why any animal would suffocate.
The Cueva de la Muerte and its lethal pool have been famous in documentaries about Costa Rica’s natural wonders. But make no mistake – venturing inside is extremely dangerous and fatal if you get too close. This cave houses death in the unlikeliest and most innocuous disguises – a pool of invisible suffocation.