Following the road leading to Gran Serin, immediately after Alpe Arguel summer grazing land, you will find a barrier closing the road. On the right, the beginning of the trail climbing among larches, Swiss pines, and clearings covered with rhododendrons, until you meet trail no. 13. In about 15 minutes you will reach Colle dell'Assietta at 2,472m of altitude. Both end along the SP road 173.