Take the road from Gargnano to Valvestino until you reach the crossroads (0,0 km) near the village of Navazzo where you can park. You start pedaling toward Briano, leaving behind the lake and then reach the village of Formaga (1,5 km), just beyond which the slope becomes more sustained. The road rises up to Montecastello di Gaino and Pizzocolo, back to the lake for some stretches and then reaches Bocchetta del Santo di Liano (750 m asl) and the crossroads for Briano. The direction to take is the one on the left for Costa: you then pedal a road that alternating with uphill and downhill leads to Bocca Magno (6,6 km, 788 m asl), where you can see in the distance the village of Costa. The following section of the itinerary crosses an area of extensive meadows and pastures, and runs along a long descent, and then another section on which you can easily go until the bridge over the Rio della Costa (665 m). From here it passes a stretch of marked slope to reach the church of San Bartolomeo and the village of Costa (11,4 km). It continues among the houses on the road that reaches the nearby small hamlet of Mignone (768 m slm), from which on the dirt road it goes into the woods. It passes by a fountain and after a kilometer you reach a junction where you continue straight to Lake Valvestino (indication). Behind the ruin of an old building with a view of the artificial lake in the locality of Casali (699 m) is continued for a short section up to a junction where we keep to the right, keeping parallel to Lake Valvestino as far as the hamlet of Lignago (15.6 km, 550 m asl). From here we turn onto the asphalt road that connects Valvestino to Gargnano: we turn left, continuing to skirt the artificial reservoir as far as the dam and then until we reach and pass the village of Navazzo, returning after a few hundred metres to the starting point.