The leg cannot be travelled at the moment because maintenance and improvement activities are in progress on the route. We suggest taking the B21 Viterbo-Vetralla variant (link) or the B21 Viterbo-Sutri variant (link).

Starting from Piazza del Sacrario, one crosses Piazza del Plebiscito until exiting the medieval walls of Viterbo through Porta Romana; one passes under Porta San Biele and then Via della Grotticella before climbing up Strada Roncone. From here begins a path through chestnut and oak woods until reaching the village of San Martino al Cimino, a hamlet of Viterbo. You enter San Martino al Cimino through the North Gate, skirting the famous 13th-century Cistercian Abbey; after crossing the entire village, you exit through the South Gate. After a few kilometres on easy undergrowth paths and a few stretches on asphalt roads with panoramic views north towards Montefiascone, we enter the woods of Monte Fogliano along shady paths that descend towards the village of Tre Croci, a hamlet of Vetralla. From Tre Croci, there is a short stretch of dirt road that reaches Vetralla, crossing Foro Cassio.