The streams Felizon and Travenanzes, and the rio Ra Vales have dug very
deep ravines in the dolomite rock at the bottom of the valley, which
has therefore a rough and wild aspect. The respective canyons can be
crossed only through some bridges dating back to the times of the first
communication systems linking the Ampezzo valley, the Pusteria and
Marebbe valleys: they are the bridge Felizon on the road di Alemagna, the bridge Outo, and the bridge of the Cadorìs on the rio Travenanzes.
Despite having carried out a deep erosion, the streams Boite and Fanes are less narrow and deep and form characteristic small waterfalls which are evident on the Boite under the plain of Malga Ra Stua.