Erratic boulders: silent witnesses of the past
|(CH 1903)||E 689339||N 72557||H 195.0|
|(WGS 84)||Long. 8.588||Lat. 45.799|
Serpentinite is a metamorphic rock formed from peridotite, typical of the upper mantle. It consists predominantly of serpentine, a mineral silicate typically green in colour. At the base of this erratic boulder there is a roughly cylindrical cavity (almost always hidden below the level of the lake) known as “pot of the giants”, produced by prolonged abrasion by detritus on the rock, under the force of turbulent currents and whirlpools of water. The cavity, located at the base of the stone on the side towards the lake, is visible only during periods when the lake water is at a low level.
From Sesto Calende, take the S.P. 69, which follows the eastern shore of the lake north, and exit towards the center of Ranco. The site is located a few hundred metres east of the centre of the village.
The site is marked by signs. Recent renovations along the shores of the lake have made the trail quite easy to follow.