A round trip that takes us to the old Austro-Hungarian border and the nearby man-made Valvestino lake.

Starting from the biologic oil mill in Tignale, head uphill towards the village of Olzano. Turn left at the end of Via S. Lorenzo and follow trail no. 253 towards the Cima Piemp mountain hut.
On arrival to the mountain hut, keep to the left and follow the old soldiers’ road for about five kilometres until you reach Passo d'Ere. From here head towards Bocca Paolone. At this junction, keep to the right and follow the path downhill that to the bottom of the valley. Follow the trail no. 249 until you cross trail no. 250 and then follow the signs for the village Costa. From this characteristic village, in around two kilometres, you reach Bocca Paolone again and follow the signpost 253 to the right.
Cross Passo Fobia, the Cuel water fountain and take the path that takes us in the direction of Aer (signpost 251). To return to the starting point from Aer, simply follow the flat Via Panoramica for about two kilometres.