The morainic hills, which water-courses have modified through the ages, bear witness to the great glaciations of the Quaternary period. One example is the hilly land in the municipality of Usmate Velate, near Cassinetta where the escarpment formed after the earliest glaciation (480,000 years ago) is clearly visible. Since the 90’s the 17 hectares of the Cassinetta woods have been “adopted” by the local section of Legambiente and have become a place to experiment collective management of a natural environment. Volunteers team up to create and maintain paths and to reforest the woods and give training in the care of the environment with moments of debate and festivity. The woods, a priceless refuge for owls, weasels and squirrels, are dominated by the North American robinia pseudo acacia but there are also chestnuts, oaks, wild apple and cherry trees.