In Maloja there is the largest concentration of giants' mills from all over Europe.
These cavities were discovered in 1882 during the construction of the Belvedere Castle - today the Belvedere Tower.
After the last Ice Age about 1000 years ago, the glaciers retreated from the lowlands. A large quantity of meltwater and glacier ice have been released, as well as stones and sand have been carried along with it. Normally, this resulted in smooth rock surface or scarring, but more rarely in glacial potholes such as in this case. This is because meltwater seeks a path through the ice crevasses and at high pressure the water with entained sand hitted the rocky ground. The abrasive effect at the same place and depending on the duration and hardness of the rock, these glacial pothole of different depths were formed. Many glacial potholes are filled with water beacuse they have no drainage in the rock. Some are covered with sand and stone since the glacier retreat and therefore remain hidden. 36 glacial potholes have been exposed in the area northwest Maloja.
A nature trail with information boards satisfies the curiosity for konwledge about the phenomenon of the glacial mill and also explains the botanical rarities found here.