In Val Menaggio there is a small lake called Piano Lake with an area of almost 85 hectares square and a maximum height of 13 meters is located in the valley behind Porlezza.
During the winter, the lake is a feature of ice fishing, for a period between December and early February, due to the shade projected by Mount Galbiga; The icy surface makes skating possible creating picturesque and suggestive atmospheres.
The lake is part of a Regional Nature Reserve and is also recognized by the European Union, covering an area of 203 hectares. It is considered the ideal continuation of Lake Lugano as an appendage of the same but separate from the floods of the river Cuccio, which have created a large filling area. Different and very close habitats make the area important with specimens of typical and very rare plants in the wetland; Also from the historical point of view, with its testimonies of past populations such as the medieval village of Castel S.Pietro, the ancient mills, the Lembra washbasin, the dry walls and the traditional farmhouses. The village rises on an ancient site of observation and signaling of Roman era characterized by a luminous tower which, connected to those in Carlazzo and Towers, constituted a visual signal line.
Wildlife includes over 140 species of birds and numerous mammals including deer and roe deer; Fish, amphibians and game are affected by the nearby green lung of Mount Galbiga; Among the peculiar species is the presence of austropotamobius shrimp.
At the slopes of Mount Galbiga is located the Polyvalent Naturalistic Observatory, which has the main purpose of the natural reserve promotion with various participation programs. The guided educational naturalistic itinerary has as its starting point and arrival the reserve house, a structure open all year round which also has an ecomuseum inside it.