Sasso Malascarpa Nature Reserve was established according to art. 37 of the Regional law n. 86/83. It is one of the most interesting areas in Lombardy under the geological, geomorphological, and paleonthological point of view. The protected territory covers an overall area of 196 hectares, partly situated in the Municipality of Canzo, on the left bank of the Ravella stream and it is a property of Demanio Forestale Regionale (Regional Forest Authority). The rest of the Nature Reserve is situated in the Municipality of Valmadrera, on the left slope of Val Molinata and partially overlaps Parco di interesse sovracomunale di S. Tomaso.