Near the stream in Val Maliens there is a whole series of water-filled glacial mills, linked together like a pearl necklace. The vessel-shaped hollows, with diameters ranging from a few decimetres to several metres, are usually filled with crystal-clear water, and some of them also contain pebbles. Watching the water trickle like a cascade from one hollow to the next is a real wonder of nature.

It is not known exactly how old these mills are. They should not be confused with glacial potholes dating from the end of the last Ice Age.

The origins of the Strudelkolke pothole in Val Maliens can be explained by the gradient, stratification of the stone, and finally differences in hardness in the local area. The erosive effect of the stream has penetrated the overlying upper layers of the Malm limestone. The water, with the aid of sand and pebbles, has hollowed out the steps in the softer layers of rock underneath.
The glacier mills are all found in the lime-dissolving karst rock. It is still unclear whether the leaching of carbonated water has an influence on the configuration of the whirlpools. Lime-dissolving or corrosive processes may at least have played a part at the place of origin, and may also have reinforced the erosive effect of the water.