On Mount Etna it is possible to find 200 volcanic caves. Most of them are in a vertical or sub vertical development. Only few of them are horizontal or sub horizontal and these ones are clearly easier to visit thanks to the assistance of a guide and the use of helmets and lights. The visit does not require any special equipment like ladders, ropes, slings or carabineers. Formation stages of Mount Etna caves: the formation of the cave starts with an eruptive event, with the formation of a lava flow on a slope. The second stage is the formation of embankments on which lava flows fairly smooth, but still in the open air. The third stage is one of the most important and determines the cross sections. In this stage we have the formation of a lava tube. During the fourth stage the lava flow decreases and this promotes the formation of stalactites almost solidified, hanging from the ceiling or like shelves along the walls. During the fifth and last stage there is a further decrease of the lava flow. In the final phase the lava tunnel is formed and solidified.