If the temperatures rise above 30 degrees and make us sweat a lot, then a visit to the Eternal Ice in Dornburg is recommended, where the outside temperatures are a pleasant 20 degrees and very close to the mountain even drop to 3 degrees.
Everyone has probably heard of the eternal ice in Dornburg. I was also familiar with it, but unfortunately I had never been there myself in all those years. Due to a professional appointment, I was lucky enough to get to know this place for the first time. Coming from Frickhofen in the direction of Wilsenroth, there is a small car park on the right after the building yard, from which it is 300 meters to the Eternal Ice. The closer I get to the spot, the noticeably cooler it gets.
Cool air from the mountain
The place itself seems quite inconspicuous at first. Two large, barred openings allow a view of the mountain. You are at the end of a slope covered with basalt boulders. A clear draft can be felt in front of the openings. There is still snow in one of the openings. It was shoveled in in winter so that visitors to this place can get an idea of how cold it is in the mountain, Joachim Habel from the Frickhofen Culture and History Association explained to me. The thermometer goes down in no time and stays at 3 degrees Celsius. It was a funny coincidence, because only one day later the Hessenschau was there and reported on the coolest place in Hessen.
Since the eternal ice is a unique natural phenomenon in the Westerwald, it is part of the Geopark Westerwald-Lahn-Taunus. In 1839, while demolishing basalt rock, workers discovered icing beneath the mass of rubble. Deep in the mountain, the rocks are frozen to a depth of eight meters. Now with the hot temperatures, this ice is not visible. It would also make no sense to remove stones, because then the ice would melt very quickly because of the lack of insulation.
The mountain made of basalt rock has numerous cracks and crevasses that promote ice formation. Furthermore, this is favored by the large difference in height between the inlet and outlet openings for the air. These are all prerequisites for a chimney effect to occur. The rubble on the slope has a heat-insulating effect. The incoming warm air from outside penetrates the mountain and cools down. Cold air is heavier and sinks downwards - thereby drawing new air into this "chimney" from above. The cold air flows back out at the two ends of the tunnel. This cool draft can be felt very well when you stand in front of it.
From there it is worth a slight climb to the Hildegardisfelsen, from which there is a wonderful view. The Hildegardis chapel and the fountain as well as the Celtic wall at the former Dornburg can also be discovered there. They are all part of the Blasiussteig. An interesting area on the doorstep and a recommended visit given the current temperatures.