The Great Cave, result of the work of time and water

Stalactites and stalagmites

The action of underground water has resulted in stalactites, stalagmites, the many "sculptures" of the Great Cave.

Ammonites and lakes

Calcites from the shells of ammonites that more than 60 000 million years ago are also identifiable.

The caves of Arcy and mainly the Great Cave result from the work of time and water after the withdrawal of the warm sea that covered the region 150 million years ago. The Cure river which has its source in the Morvan has dug into the soft Arcy limestone massif while the circulation and runoff waters heavily loaded with calcium has contributed to the development of a so-called "karst landscape".