Passo della sentinella ( 2717 m ) it's famous for the beauty of the valleys that dominates ( Val Fiscalina and Vallon Popera ) and of the fantastic dolomitic peaks on its sides ( on the left Cima Undici, 3092 m and on the right Croda Rossa di Sesto, 2965 m .
During the first world war this pass was theatre of one of the most heroic exploits of the war. The austrians would control the summit of Croda Rossa di Sesto so for the italians was very important to conquer the pass. In the spring of 1916 the group called "I Mascabroni" ( the tough guys, the fearless soldiers ) managed to set a position on Cima Undici and slowly ( during the night ) started to secure with ladders and ropes the crest of the mountain. All this done in extreme weather conditions at 3000 meters of altitude. The 15 of April they attacked the austrians from 2 sides and won the battle. An extraordinary military but mostly alpinistic exploit.