The caves comprise four fossilised levels and an active level. There are a variety of stunning limestone rock formations and remarkable effects caused by erosion including an exceptional coffered ceiling on the first level. The guided tour begins on the upper level which contains galleries and caves with wonderful formations. The tour then descends 80 metres down a chasm to reach the underground river level. A boat takes you 150 metres along two faults 80 metres deep where the successive levels of the river bed can be seen. You take the little train for the 700 metre underground journey back to the surface.