Leave Mesón de Salinas and take the A-2609 heading to the valley of Chistau in the direction of Plan. The first kilometres are fairly flat and will allow an easy ride. After leaving the Saravillo detour behind we turn right at the next one and head towards Sin, Señes and Serveto in the La Comuna valley. We descend to cross the Cinqueta bridge and then begin to climb. The first three kilometres are horrifying with slopes averaging 10% and some even peaking above 15%. It’s what you might call a real wall which climbs up a stony terrain without any trees to offer shade. At first it draws out a wide Z and then winds into several horseshoe curves further up. We now arrive at the Sin detour. The road passes above the town and offers us milder slopes during the last kilometres although it does have a few steep sections which remind us of those brutal percentages we left behind. The finish line is in Serveto at an altitude of 1,361 m.