This natural phenomenon can be explained by the physical principle of wind tubes: a column system in the Porphyry stone causes a continuous cold draught. The heavy cold air stays as a pool of cold air in the hollow and escapes from the lower holes, the Ice Holes (Eislöcher, in German), as cold air featuring a temperature of 0 - 9 degrees C. Due to the cool climate, plants thrive here in the protected forest of Appiano Monte (Eppan Berg) at 500 m a.s.l., which normally can be found in higher alpine regions.

The Ice Holes are located near Pianizza di Sopra (Oberplanitzing), a district of Caldaro, where our hike starts. The tour, very popular among families with children, leads us on the trail no. 15 to the Ice Holes. Afterwards we hike back on the same path.

A possibility to extend the hike is to start at the main square of San Michele Appiano. Behind the little St. Anna Church, the path no. 7A branches off to the right. It proceeds past Castel Ganda to the Stroblhof and continues on the path no. 15 for about 20 minutes towards south. On the path you can already feel the refreshing cool. The path no. 7A leads straight back to the Steinegger tavern, then the trail ST continues to the starting point in San Michele Appiano.