A vast natural arch of grey limestone, around fifty metres wide and forty high, spanning a small valley north-west of Sant'Anna d'Alfaedo. It is the collapsed remnant of a karst cave, and one of the largest natural bridges in Europe. The cliffs around it shelter shallow caves that were inhabited from the Middle Palaeolithic onward, with finds going back more than 60,000 years.
The bridge is reached on foot in about ten minutes from a small car park on the road from Fosse, or from the trattorias clustered around the upper viewpoint. In summer, swallows nest in the rock face and their cries fill the valley.