These cellars use natural properties of the terrain. In Switzerland, there are many places where it is naturally colder than the rest of the environment. At the foot of rubble slopes it is often colder because inside the rubble the air can sink and cool down. The water present in the rubble evaporates, contributing to the cooling. In earlier times, buildings were built where the cold air escapes from below, which then served as natural refrigerators.
There are still such cellars in my area. Here is an article with pictures about it (in German): https://www.gasthaus-kreuz.ch/Archiv/reportagen_bierchaeller.... It is likely that comparable natural phenomena have been used in other countries as well.