Ewiges Eis

Ewiges Eis is a natural ice formation in Dornburg, Germany, which extends under basalt rubble to roughly 2 meters depth. Below that level, the ground stays frozen down to 8 meters, even when summer temperatures rise outside.

Workers encountered the ice layers in June 1839 while extracting road construction material, which led to scientific examinations. Researchers used this discovery to explain the low spring temperatures in the surrounding area.

The name refers to the year-round cold inside the tunnels, where ice can persist even during summer. A brewer used the cooling effect from 1869 for beer production and created two access passages for that purpose.

Two tunnel openings fitted with iron grilles provide access to the cold air streaming from the rock during summer. The draft is most noticeable on warm days.

The temperature differences between top and bottom create a chimney effect that continuously drives air through the rock crevices. This natural cycle prevents the ice from melting even when the outside heat is intense.

Location: Dornburg

Part of: Westerwald-Lahn-Taunus Geopark

GPS coordinates: 50.51984,8.02445

Latest update: December 5, 2025 16:30