The cave system of Kap-Kutan or more precisely Cupp-Coutunn is despite its somewhat remote location one of the few caves mentioned in classic literature. The historian DIODORUS described the caves as early as 49 B.C. in his book 'Biblioteca Historica' ! Knowledge of the caves got lost for many centuries until the early 1950, when a russian geologists visited them and made a proposal for mining its wealth of banded onyx as ornamental stone. Mining started in the late 50s and continued for 20 years, before it was stopped by a growing nature conservation movement.

The geology of the cave system is rather complex. A thick limestone sucession of upper jurassic age was intruded by volcanic rocks and granites in later times. These intrusions brought along hot sulphuric solutions, which formed the caves and the magnificient speleothems.

Against the well known extraordinary beauty of Lechuguilla cave  the Kap - Kutan system compares at least equal - if not even more spectacular - to its american counterpiece.

Kap-Kutan is another example of cave formation by sulphuric acid solutions, resulting in a very long cave system with spectacular and sometimes very large decoration made up of different minerals such as aragonite, calcite, hydromagnesite and gypsum. The aragonite and gypsum form large chandeliers and crystal aggregates which may reach a length of 4 meter and more. Though they are generally not single crystals, individual crystals may easily reach a size of more than one meter.

Apart from the beautiful aragonite and gypsum speleothems in the cave system there appear to occur also large calcite crystals with a dimension  of up to 2 m as freely crystallized crystals on some cave walls.

The Kap Kutan cave system is definitely one of the most remarkable cave system in the world, displaying a vast and rich variety of remarkable speleothem decoration and consequently needs strict protection.