Itinerary that leads to the foot of the Schiara, the highest elevation of the park with its 2,565 meters high, going up the steep Ardo valley.
From the parking lot of Bortot houses take the CAI path 501, which coincides with the final stretch of the Alta Via n. 1. Shortly after the departure, on the right you will find the indications for the ring route of the Bus del Buson: an interesting educational itinerary that allows you to visit a spectacular fossil canyon. If you decide to visit the ravine, you need to consider a time of about three quarters of an hour and an additional difference in height of about 100 meters downhill and as many uphill; otherwise, continue on the main mule track, which descends on the Ardo stream to the confluence with the Rui Frèt in Mariano (681 m). From here, the path begins to climb steeply up into the woods. Higher up the route crosses the Ardo several times, skirting spectacular waterfalls and forms of erosion created by the water up to the final stretch, called "il Calvario", which leads to the 7° Alpini refuge.
The refuge is the starting point for accessing the spectacular and challenging iron paths that run along the south face of the Schiara.