The name Actun Tunichil Muknal comes from the Maya language and means something like 'Cave of the Crystal Sepulchre'. It is a fitting name because over thousands of years, the dripping water inside the cave has coated everything in a sparkling layer of calcite crystals, giving the ancient pottery and rock formations an almost magical, glittering appearance.
The cave was rediscovered by explorers in the 1980s and opened carefully for guided visits. To get inside, you hike through the jungle, cross three rivers on foot, and then swim a short distance into the cave entrance. Once inside, you put on a helmet with a lamp and explore chambers that the ancient Maya once considered very special.
Inside, the cave is full of extraordinary formations — stalactites hanging from the ceiling and stalagmites rising from the floor, all coated in that glittering crystalline layer. The ancient pottery jars left by the Maya have also been coated over time and glitter beautifully in torchlight.
Only small guided groups are allowed inside ATM Cave each day, and visitors must be very careful not to touch anything. This helps protect the sparkling crystals and the ancient objects so they stay beautiful for future generations to see.