They were discovered in February 1861. Such caves are made of crystalline formations and great amount of stalagmites and stalactites. The interior passages descend looking for the aquifer, ending up in lakes with crystal waters.

Located in a region of loamy limestone marine terraces, it is 3,1 kms. Tours cover 1500 m (5000 feet) of it, including some of its 17 galleries, 6 halls and a corridor. The water that drips from its walls keep its relative humidity at 100 percent, and the temperature ranges between 77? and 80.6? F. (between 25? and 27? C.).